Capsule.java

/*
 * Capsule
 * Copyright (c) 2014-2016, Parallel Universe Software Co. and Contributors. All rights reserved.
 *
 * This program and the accompanying materials are licensed under the terms
 * of the Eclipse Public License v1.0, available at
 * http://www.eclipse.org/legal/epl-v10.html
 */

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.Reader;
import java.lang.instrument.Instrumentation;
import java.lang.management.ManagementFactory;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.charset.Charset;
import java.nio.file.DirectoryStream;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import java.nio.file.StandardOpenOption;
import java.nio.file.attribute.FileAttribute;
import java.nio.file.attribute.FileTime;
import java.nio.file.attribute.PosixFileAttributeView;
import java.nio.file.attribute.PosixFilePermission;
import java.nio.file.attribute.PosixFilePermissions;
import java.security.Permission;
import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.Properties;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.RandomAccess;
import java.util.concurrent.atomic.AtomicReference;
import javax.management.MBeanServer;
import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

import static java.util.Collections.*;
import static java.util.Arrays.asList;

/**
 * An application capsule.
 * <p>
 * This API is to be used by caplets (custom capsules) to programmatically (rather than declaratively) configure the capsule and possibly provide custom behavior.
 *
 * <h2>Writing Caplets</h2>
 *
 * All non-final protected methods may be overridden by caplets. These methods will usually be called once, but they must be idempotent,
 * i.e. if called numerous times they must always return the same value, and produce the same effect as if called once.
 * <br>
 * Overridden methods need not be thread-safe, and are guaranteed to be called by a single thread at a time.
 * <br>
 * Overridable (non-final) methods <b>must never</b> be called directly by caplet code, except by their overrides.
 * <p>
 * Final methods implement various utility or accessors, which may be freely used by caplets.
 * <p>
 * Caplets might consider overriding some of the following powerful methods:
 * {@link #attribute(Map.Entry) attribute}, {@link #getVarValue(String) getVarValue},
 * {@link #prelaunch(List, List) prelaunch}.
 * <p>
 * For command line option handling, see {@link #OPTION(String, String, String, String) OPTION}.<br/>
 * Attributes should be registered with {@link #ATTRIBUTE(String, Object, Object, boolean, String)  ATTRIBUTE}.
 *
 * <h3>Handling Files</h3>
 *
 * Capsule uses a two-staged <i>file resolution mechanism</i>.
 *
 * When a manifest property contains a reference to anything that might resolve to a file (or multiple files) -- e.g. the name of a Maven artifact --
 * the string containing the reference is passed to the {@link #lookup(java.lang.String, java.lang.String, java.util.Map.Entry, java.lang.Object) lookup} method,
 * which returns an opaque handle.
 *
 * When the application launch command line is rendered (or any configuration file that is interpreted by an outside process), the file handles
 * are passed to the {@link #resolve(java.lang.Object) resolve} method, which turns the handle into a list of {@code Path}s.
 *
 * The operation of {@code lookup} and {@code resolve} can be customized by a caplet, but that process is intentionally left undocumented
 * until that process is finalized.
 *
 * @author pron
 */
public class Capsule implements Runnable, InvocationHandler {
    public static final String VERSION = "1.0.4";
    /*
     * This class follows some STRICT RULES:
     *
     * 1. IT MUST COMPILE TO A SINGLE CLASS FILE (so it must not contain nested or inner classes).
     * 2. IT MUST ONLY REFERENCE CLASSES IN THE JDK.
     * 3. ALL METHODS MUST BE PURE OR, AT LEAST, IDEMPOTENT (with the exception of the launch method, and the constructor).
     *
     * Rules #1 and #2 ensure that fat capsules will work with only Capsule.class included in the JAR. Rule #2 helps enforcing rules #1 and #3.
     * Rule #3 ensures methods can be called in any order (after construction completes), and makes maintenance and evolution of Capsule simpler.
     * This class contains several strange hacks to comply with rule #1.
     *
     * Also, the code is not meant to be the most efficient, but methods should be as independent and stateless as possible.
     * Other than those few methods called in the constructor, all others are can be called in any order, and don't rely on any state.
     *
     * We do a lot of data transformations that could benefit from Java 8's lambdas+streams, but we want Capsule to support Java 7.
     *
     * The JavaDoc could really benefit from https://bugs.openjdk.java.net/browse/JDK-4085608 to categorize methods into
     * Caplet overrides properties, and utility categories.
     *
     *
     * Caplet Hierarchy (or chain)
     * ---------------------------
     *
     * Capsule subclasses, i.e. caplets, may be arranged in a dynamic "inheritance" hierarchy, where each caplet modifies, or "subclasses"
     * the previous ones in the chain.
     * The first caplet in the chain (the highest in the hierarchy) is referenced by the 'oc' field, the last is referenced by 'cc', and
     * the previous caplet, the "superclass" is referenced by 'sup':
     *
     *  ____          ____          ____          ____
     * |    |   sup  |    |   sup  |    |   sup  |    |
     * | OC | <----- |    | <----- |    | <----- | CC |
     * |____|        |____|        |____|        |____|
     *
     * A wrapping capsule is inserted into the chain following the wrapped capsule.
     */

    //<editor-fold defaultstate="collapsed" desc="Constants">
    /////////// Constants ///////////////////////////////////
    private static final long START = System.nanoTime();
    private static final Map<String, Object[]> OPTIONS = new LinkedHashMap<>(20);
    private static final Map<String, Object[]> ATTRIBS = new LinkedHashMap<>(60);
    private static Properties PROPERTIES = new Properties(System.getProperties());

    // standard values
    private static final String PROP_JAVA_VERSION = "java.version";
    private static final String PROP_JAVA_HOME = "java.home";
    private static final String PROP_OS_NAME = "os.name";
    private static final String PROP_USER_HOME = "user.home";
    private static final String PROP_JAVA_LIBRARY_PATH = "java.library.path";
    private static final String PROP_FILE_SEPARATOR = "file.separator";
    private static final String PROP_PATH_SEPARATOR = "path.separator";
    private static final String PROP_JAVA_SECURITY_POLICY = "java.security.policy";
    private static final String PROP_JAVA_SECURITY_MANAGER = "java.security.manager";
    private static final String PROP_TMP_DIR = "java.io.tmpdir";

    private static final String ATTR_MANIFEST_VERSION = "Manifest-Version";
    private static final String ATTR_PREMAIN_CLASS = "Premain-Class";
    private static final String ATTR_MAIN_CLASS = "Main-Class";
    private static final String ATTR_CLASS_PATH = "Class-Path";
    private static final String ATTR_IMPLEMENTATION_VERSION = "Implementation-Version";
    private static final String ATTR_IMPLEMENTATION_TITLE = "Implementation-Title";
    private static final String ATTR_IMPLEMENTATION_VENDOR = "Implementation-Vendor";
    private static final String ATTR_IMPLEMENTATION_URL = "Implementation-URL";

    private static final String FILE_SEPARATOR = System.getProperty(PROP_FILE_SEPARATOR);
    private static final char FILE_SEPARATOR_CHAR = FILE_SEPARATOR.charAt(0);
    private static final String PATH_SEPARATOR = System.getProperty(PROP_PATH_SEPARATOR);
    private static final String MANIFEST_NAME = "META-INF/MANIFEST.MF";

    // Operating systems
    private static final String OS_WINDOWS = "windows";
    private static final String OS_MACOS = "macos";
    private static final String OS_LINUX = "linux";
    private static final String OS_SOLARIS = "solaris";
    private static final String OS_BSD = "bsd";
    private static final String OS_AIX = "aix";
    private static final String OS_HP_UX = "hp-ux";
    private static final String OS_UNIX = "unix";
    private static final String OS_POSIX = "posix";
    private static final String OS_VMS = "vms";

    private static final String OS = getProperty(PROP_OS_NAME).toLowerCase();

    private static final Set<String> PLATFORMS = immutableSet(OS_WINDOWS, OS_MACOS, OS_LINUX, OS_SOLARIS, OS_BSD, OS_AIX, OS_POSIX, OS_UNIX, OS_POSIX, OS_VMS);
    private static final String PLATFORM = getOS();

    private static final String ENV_CACHE_DIR = "CAPSULE_CACHE_DIR";
    private static final String ENV_CACHE_NAME = "CAPSULE_CACHE_NAME";

    // misc
    private static final String CAPSULE_PROP_PREFIX = "capsule.";
    private static final String CACHE_DEFAULT_NAME = "capsule";
    private static final String APP_CACHE_NAME = "apps";
    private static final String LOCK_FILE_NAME = ".lock";
    private static final String TIMESTAMP_FILE_NAME = ".extracted";
    private static final String CACHE_NONE = "NONE";
    private static final String SEPARATOR_DOT = "\\.";
    private static final Path WINDOWS_PROGRAM_FILES_1 = Paths.get("C:", "Program Files");
    private static final Path WINDOWS_PROGRAM_FILES_2 = Paths.get("C:", "Program Files (x86)");
    private static final int WINDOWS_MAX_CMD = 32500; // actually 32768 - http://blogs.msdn.com/b/oldnewthing/archive/2003/12/10/56028.aspx
    private static final ClassLoader MY_CLASSLOADER = Capsule.class.getClassLoader();
    private static final Permission PERM_UNSAFE_OVERRIDE = new RuntimePermission("unsafeOverride");
    private static final int SOCKET_TIMEOUT = 30000; // Keep high enough for container-based capsules

    // Lifecycle
    private static final int STAGE_NONE = 0;
    private static final int STAGE_LAUNCH = 1;
    private static final int STAGE_LIFTOFF = 2;

    // options
    private static final int OPTION_DEFAULT = 0;
    private static final int OPTION_METHOD = 1;
    private static final int OPTION_WRAPPER_ONLY = 2;
    private static final int OPTION_DESC = 3;

    // attributes
    private static final int ATTRIB_TYPE = 0;
    private static final int ATTRIB_DEFAULT = 1;
    private static final int ATTRIB_MODAL = 2;
    private static final int ATTRIB_DESC = 3;

    // messages
    private static final int MESSAGE_EXIT = 1;
    private static final int MESSAGE_START_JMX = 2;
    private static final int MESSAGE_JMX_URL = 3;

    // properties
    private static final String PROP_VERSION = OPTION("capsule.version", "false", "printVersion", "Prints the capsule and application versions.");
    private static final String PROP_MODES = OPTION("capsule.modes", "false", "printModes", "Prints all available capsule modes.");
    private static final String PROP_PRINT_JRES = OPTION("capsule.jvms", "false", "printJVMs", "Prints a list of all JVM installations found.");
    private static final String PROP_MERGE = OPTION("capsule.merge", null, "mergeCapsules", true, "Merges a wrapper capsule with a wrapped capsule.");
    private static final String PROP_HELP = OPTION("capsule.help", "false", "printHelp", "Prints this help message.");
    private static final String PROP_INTROSPECT = OPTION("capsule.introspect", "false", "introspect", "Prints the values of all attributes.");
    private static final String PROP_MODE = OPTION("capsule.mode", null, null, "Picks the capsule mode to run.");
    private static final String PROP_RESET = OPTION("capsule.reset", "false", null, "Resets the capsule cache before launching. The capsule to be re-extracted (if applicable), and other possibly cached files will be recreated.");
    private static final String PROP_LOG_LEVEL = OPTION("capsule.log", "quiet", null, "Picks a log level. Must be one of none, quiet, verbose, or debug.");
    private static final String PROP_CAPSULE_JAVA_HOME = OPTION("capsule.java.home", null, null, "Sets the location of the Java home (JVM installation directory) to use; If \'current\' forces the use of the JVM that launched the capsule.");
    private static final String PROP_CAPSULE_JAVA_CMD = OPTION("capsule.java.cmd", null, null, "Sets the path to the Java executable to use.");
    private static final String PROP_JVM_ARGS = OPTION("capsule.jvm.args", null, null, "Sets additional JVM arguments to use when running the application.");
    private static final String PROP_PORT = "capsule.port";
    private static final String PROP_ADDRESS = "capsule.address";
    private static final String PROP_TRAMPOLINE = "capsule.trampoline";
    private static final String PROP_PROFILE = "capsule.profile";

    /*
     * Map.Entry<String, T> was chosen to represent an attribute because of rules 1 and 2.
     */
    /**
     * The application's name. E.g. {@code "The Best Word Processor"}
     */
    protected static final Entry<String, String> ATTR_APP_NAME = ATTRIBUTE("Application-Name", T_STRING(), null, false, "The application's name");
    /**
     * The application's unique ID. E.g. {@code "com.acme.bestwordprocessor"}
     */
    protected static final Entry<String, String> ATTR_APP_ID = ATTRIBUTE("Application-Id", T_STRING(), null, false, "The application's name");
    protected static final Entry<String, String> ATTR_APP_VERSION = ATTRIBUTE("Application-Version", T_STRING(), null, false, "The application's version string");
    protected static final Entry<String, List<String>> ATTR_CAPLETS = ATTRIBUTE("Caplets", T_LIST(T_STRING()), null, false, "A list of names of caplet class names or Maven coordinates of caplet artifacts that will be applied to the capsule in the order they are listed");
    private static final Entry<String, String> ATTR_LOG_LEVEL = ATTRIBUTE("Capsule-Log-Level", T_STRING(), null, false, "The capsule's default log level");
    private static final Entry<String, String> ATTR_MODE_DESC = ATTRIBUTE("Description", T_STRING(), null, true, "Contains the description of its respective mode");
    protected static final Entry<String, String> ATTR_APP_CLASS = ATTRIBUTE("Application-Class", T_STRING(), null, true, "The main application class");
    protected static final Entry<String, String> ATTR_APP_ARTIFACT = ATTRIBUTE("Application", T_STRING(), null, true, "The Maven coordinates of the application's main JAR or the path of the main JAR within the capsule");
    protected static final Entry<String, Object> ATTR_SCRIPT = ATTRIBUTE("Application-Script", T_FILE(), null, true, "A startup script to be run *instead* of `Application-Class`, given as a path relative to the capsule's root");
    protected static final Entry<String, String> ATTR_MIN_JAVA_VERSION = ATTRIBUTE("Min-Java-Version", T_STRING(), null, true, "The lowest Java version required to run the application");
    protected static final Entry<String, String> ATTR_JAVA_VERSION = ATTRIBUTE("Java-Version", T_STRING(), null, true, "The highest version of the Java installation required to run the application");
    protected static final Entry<String, Map<String, String>> ATTR_MIN_UPDATE_VERSION = ATTRIBUTE("Min-Update-Version", T_MAP(T_STRING(), T_STRING(), null), null, true, "A space-separated key-value ('=' separated) list mapping Java versions to the minimum update version required");
    protected static final Entry<String, Boolean> ATTR_JDK_REQUIRED = ATTRIBUTE("JDK-Required", T_BOOL(), false, true, "Whether or not a JDK is required to launch the application");
    protected static final Entry<String, Boolean> ATTR_AGENT = ATTRIBUTE("Capsule-Agent", T_BOOL(), false, true, "Whether this capsule should inject itself as an agent into the application.");
    private static final Entry<String, List<String>> ATTR_ARGS = ATTRIBUTE("Args", T_LIST(T_STRING()), null, true,
            "A list of command line arguments to be passed to the application; the UNIX shell-style special variables (`$*`, `$1`, `$2`, ...) can refer to the actual arguments passed on the capsule's command line; if no special var is used, the listed values will be prepended to the supplied arguments (i.e., as if `$*` had been listed last).");
    private static final Entry<String, Map<String, String>> ATTR_ENV = ATTRIBUTE("Environment-Variables", T_MAP(T_STRING(), T_STRING(), null), null, true, "A list of environment variables that will be put in the applications environment; formatted \"var=value\" or \"var\"");
    protected static final Entry<String, List<String>> ATTR_JVM_ARGS = ATTRIBUTE("JVM-Args", T_LIST(T_STRING()), null, true, "A list of JVM arguments that will be used to launch the application's Java process");
    protected static final Entry<String, Map<String, String>> ATTR_SYSTEM_PROPERTIES = ATTRIBUTE("System-Properties", T_MAP(T_STRING(), T_STRING(), ""), null, true, "A list of system properties that will be defined in the applications JVM; formatted \"prop=value\" or \"prop\"");
    protected static final Entry<String, List<Object>> ATTR_APP_CLASS_PATH = ATTRIBUTE("App-Class-Path", T_LIST(T_FILE()), null, true, "A list of JARs, relative to the capsule root, that will be put on the application's classpath, in the order they are listed");
    protected static final Entry<String, Boolean> ATTR_CAPSULE_IN_CLASS_PATH = ATTRIBUTE("Capsule-In-Class-Path", T_BOOL(), true, true, "Whether or not the capsule JAR itself is on the application's classpath");
    protected static final Entry<String, List<Object>> ATTR_BOOT_CLASS_PATH = ATTRIBUTE("Boot-Class-Path", T_LIST(T_FILE()), null, true, "A list of JARs, dependencies, and/or directories, relative to the capsule root, that will be used as the application's boot classpath");
    protected static final Entry<String, List<Object>> ATTR_BOOT_CLASS_PATH_A = ATTRIBUTE("Boot-Class-Path-A", T_LIST(T_FILE()), null, true, "A list of JARs dependencies, and/or directories, relative to the capsule root, that will be appended to the applications default boot classpath");
    protected static final Entry<String, List<Object>> ATTR_BOOT_CLASS_PATH_P = ATTRIBUTE("Boot-Class-Path-P", T_LIST(T_FILE()), null, true, "A list of JARs dependencies, and/or directories, relative to the capsule root, that will be prepended to the applications default boot classpath");
    protected static final Entry<String, List<Object>> ATTR_LIBRARY_PATH_A = ATTRIBUTE("Library-Path-A", T_LIST(T_FILE()), null, true, "A list of JARs and/or directories, relative to the capsule root, to be appended to the default native library path");
    protected static final Entry<String, List<Object>> ATTR_LIBRARY_PATH_P = ATTRIBUTE("Library-Path-P", T_LIST(T_FILE()), null, true, "a list of JARs and/or directories, relative to the capsule root, to be prepended to the default native library path");
    protected static final Entry<String, String> ATTR_SECURITY_MANAGER = ATTRIBUTE("Security-Manager", T_STRING(), null, true, "The name of a class that will serve as the application's security-manager");
    protected static final Entry<String, String> ATTR_SECURITY_POLICY = ATTRIBUTE("Security-Policy", T_STRING(), null, true, "A security policy file, relative to the capsule root, that will be used as the security policy");
    protected static final Entry<String, String> ATTR_SECURITY_POLICY_A = ATTRIBUTE("Security-Policy-A", T_STRING(), null, true, "A security policy file, relative to the capsule root, that will be appended to the default security policy");
    protected static final Entry<String, Map<Object, String>> ATTR_JAVA_AGENTS = ATTRIBUTE("Java-Agents", T_MAP(T_FILE(), T_STRING(), ""), null, true, "A list of Java agents used by the application; formatted \"agent\" or \"agent=arg1,arg2...\", where agent is either the path to a JAR relative to the capsule root, or a Maven coordinate of a dependency");
    protected static final Entry<String, Map<Object, String>> ATTR_NATIVE_AGENTS = ATTRIBUTE("Native-Agents", T_MAP(T_FILE(getNativeLibExtension()), T_STRING(), ""), null, true,
            "A list of native JVMTI agents used by the application; formatted \"agent\" or \"agent=arg1,arg2...\", where agent is either the path to a native library, without the platform-specific suffix, relative to the capsule root. The native library file(s) can be embedded in the capsule or listed as Maven native dependencies using the Native-Dependencies-... attributes.");
    protected static final Entry<String, List<Object>> ATTR_DEPENDENCIES = ATTRIBUTE("Dependencies", T_LIST(T_FILE()), null, true, "A list of Maven dependencies given as groupId:artifactId:version[(excludeGroupId:excludeArtifactId,...)]");
    protected static final Entry<String, Map<Object, String>> ATTR_NATIVE_DEPENDENCIES = ATTRIBUTE("Native-Dependencies", T_MAP(T_FILE(getNativeLibExtension()), T_STRING(), ""), null, true, "A list of Maven dependencies consisting of native library artifacts; each item can be a comma separated pair, with the second component being a new name to give the download artifact");

    // outgoing
    private static final String VAR_CAPSULE_APP = "CAPSULE_APP";
    private static final String VAR_CAPSULE_DIR = "CAPSULE_DIR";
    private static final String VAR_CAPSULE_JAR = "CAPSULE_JAR";
    private static final String VAR_CLASSPATH = "CLASSPATH";
    private static final String VAR_JAVA_HOME = "JAVA_HOME";

    private static final String PROP_CAPSULE_JAR = "capsule.jar";
    private static final String PROP_CAPSULE_DIR = "capsule.dir";
    private static final String PROP_CAPSULE_APP = "capsule.app";

    private static final String PROP_CAPSULE_APP_PID = "capsule.app.pid";

    // logging
    private static final String LOG_PREFIX = "CAPSULE: ";
    private static final String LOG_AGENT_PREFIX = "CAPSULE AGENT: ";
    protected static final int LOG_NONE = 0;
    protected static final int LOG_QUIET = 1;
    protected static final int LOG_VERBOSE = 2;
    protected static final int LOG_DEBUG = 3;
    private static final int PROFILE = emptyOrTrue(System.getProperty(PROP_PROFILE)) ? LOG_QUIET : LOG_DEBUG;
    //</editor-fold>

    //<editor-fold desc="Main">
    /////////// Main ///////////////////////////////////
    protected static final PrintStream STDOUT = System.out;
    protected static final PrintStream STDERR = System.err;
    private static volatile Integer LOG_LEVEL;
    private static Path CACHE_DIR;
    private static Capsule CAPSULE;
    private static boolean AGENT;

    final static Capsule myCapsule(List<String> args) {
        if (CAPSULE == null) {
            final ClassLoader ccl = Thread.currentThread().getContextClassLoader();
            try {
                Thread.currentThread().setContextClassLoader(MY_CLASSLOADER);
                Capsule capsule = newCapsule(MY_CLASSLOADER, findOwnJarFile());
                clearContext();
                if ((AGENT || capsule.isEmptyCapsule()) && args != null && !args.isEmpty()) {
                    processCmdLineOptions(args, ManagementFactory.getRuntimeMXBean().getInputArguments());
                    if (capsule.isEmptyCapsule())
                        capsule = capsule.setTarget(args.remove(0));
                } else {
                    processOptions();
                }
                CAPSULE = capsule.oc; // TODO: capsule or oc ???
            } finally {
                Thread.currentThread().setContextClassLoader(ccl);
            }
        }
        return CAPSULE;
    }

    public static final void main(String[] args) {
        System.exit(main0(args));
    }

    /**
     * Alternative main entry point that is not using System.exit(), thus avoiding callers to be terminated
     * in an unexpected way. 
     *
     * @param args0 the command line arguments
     * @return the exit code
     */
    @SuppressWarnings({"BroadCatchBlock", "UnusedAssignment"})
    public static int main0(String[] args0) {
        List<String> args = new ArrayList<>(asList(args0)); // list must be mutable b/c myCapsule() might mutate it
        Capsule capsule = null;
        try {
            capsule = myCapsule(args);

            args = unmodifiableList(args);

            if (isWrapperFactoryCapsule(capsule)) {
                capsule = null; // help gc
                return runOtherCapsule(args);
            }

            if (runActions(capsule, args))
                return 0;

            return capsule.launch(args);
        } catch (Throwable t) {
            if (capsule != null) {
                capsule.cleanup1();
                capsule.onError(t);
            } else
                printError(t, capsule);
            return 1;
        }
    }

    public static void premain(String agentArgs, Instrumentation inst) {
        AGENT = true;
        PROPERTIES = new Properties(System.getProperties());
        Capsule capsule = null;
        try {
            processOptions();
            capsule = myCapsule(agentArgs != null ? new ArrayList<>(split(agentArgs, "\\s+")) : null);
            for (Capsule c = capsule.cc; c != null; c = c.sup)
                c.agent(inst);
        } catch (Throwable t) {
            if (capsule != null) {
                capsule.cleanup1();
                capsule.onError(t);
            } else
                printError(LOG_QUIET, t);
        }
    }

    /**
     * @deprecated marked deprecated to exclude from javadoc
     */
    public static Object getCapsule(String capletClassName) {
        return CAPSULE.cc.sup(capletClassName);
    }

    //<editor-fold defaultstate="collapsed" desc="Error Reporting">
    /////////// Error Reporting ///////////////////////////////////
    private static void printError(int level, Throwable t) {
        if (!isLogging(level))
            return;
        STDERR.print((AGENT ? "CAPSULE AGENT" : "CAPSULE") + " EXCEPTION: " + t.getMessage());
        if (hasContext() && (t.getMessage() == null || t.getMessage().length() < 50))
            STDERR.print(" while processing " + getContext());
        if (getLogLevel(getProperty0(PROP_LOG_LEVEL)) >= LOG_VERBOSE) {
            STDERR.println();
            deshadow(t).printStackTrace(STDERR);
        } else
            STDERR.println(" (for stack trace, run with -D" + PROP_LOG_LEVEL + "=verbose)");
    }

    private static void printError(Throwable t, Capsule capsule) {
        printError(LOG_QUIET, t);
        if (!AGENT && t instanceof IllegalArgumentException)
            printUsage(capsule);
    }

    private static void printUsage(Capsule capsule) {
        printHelp(capsule != null ? capsule.isWrapperCapsule() : true);
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Run Other Capsule">
    /////////// Run Other Capsule ///////////////////////////////////
    private static boolean isWrapperFactoryCapsule(Capsule capsule) {
        return capsule.isFactoryCapsule() && capsule.isWrapperCapsule() && capsule.getJarFile() != null;
    }

    private static int runOtherCapsule(List<String> args) {
        final Path jar = CAPSULE.getJarFile();
        CAPSULE = null; // help gc
        return runMain(jar, args);
    }

    private static int runMain(Path jar, List<String> args) {
        final String mainClass;
        try {
            mainClass = getMainClass(jar);
            if (mainClass == null)
                throw new IllegalArgumentException("JAR file " + jar + " is not an executable (does not have a main class)");
        } catch (RuntimeException e) {
            throw new IllegalArgumentException(jar + " does not exist or does appear to be a valid JAR", e);
        }
        try {
            final Method main = newClassLoader0(null, jar).loadClass(mainClass).getMethod("main", String[].class);
            try {
                main.invoke(null, (Object) args.toArray(new String[0]));
                return 0;
            } catch (Exception e) {
                deshadow(e).printStackTrace(STDERR);
                return 1;
            }
        } catch (ReflectiveOperationException e) {
            throw rethrow(e);
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Command Line">
    /////////// Command Line ///////////////////////////////////
    /**
     * Registers a capsule command-line option. Must be called during the caplet's static initialization.
     * <p>
     * Capsule options are system properties beginning with the prefix "capsule.", normally passed to the capsule as -D flags on the command line.
     * <p>
     * Options can be top-level *actions* (like print dependency tree or list JVMs), in which case the {@code methodName} argument must
     * be the name of a method used to launch the action instead of launching the capsule.
     * <p>
     * Options can have a default value, which will be automatically assigned to the system property if undefined. The default values
     * {@code "true"} and {@code "false"} are treated specially. If one of them is the assigned default value, and the system property
     * is defined with with a value of the empty string, then it will be re-assigned the value {@code "true"}.
     * <p>
     * <b>Simple Command Line Options for Wrapper Capsules</b><br>
     * When the capsule serves as a wrapper (i.e. it's an empty capsule used to launch an executable artifact or another capsule)
     * then the options can also be passed to the capsule as simple command line options (arguments starting with a hyphen),
     * with the "capsule." prefix removed, and every '.' character replaced with a '-'.
     * <p>
     * These command line arguments will automatically be converted to system properties, which will take their value from the argument
     * following the option (i.e. {@code -option value}), <i>unless</i> the option is given one of the special default values
     * {@code "true"} or {@code "false"}, in which case it is treated as a flag with no arguments (note that an option with the default
     * value {@code "true"} will therefore not be able to be turned off if simple options are used).
     *
     * @param defaultValue the option's default value ({@code "true"} and {@code "false"} are specially treated; see above).
     * @param optionName   the name of the system property for the option; must begin with {@code "capsule."}.
     * @param methodName   if non-null, then the option is a top-level action (like print dependency tree or list JVMs),
     *                     and this is the method which will run the action.
     *                     The method must accept a single {@code args} parameter of type {@code List<String>}.
     * @param wrapperOnly  whether or not the option is available in wrapper capsules only
     * @param description  a description of the option.
     * @return the option's name
     */
    protected static final String OPTION(String optionName, String defaultValue, String methodName, boolean wrapperOnly, String description) {
        if (!optionName.startsWith(CAPSULE_PROP_PREFIX))
            throw new IllegalArgumentException("Option name must start with " + CAPSULE_PROP_PREFIX + " but was " + optionName);
        final Object[] conf = new Object[]{defaultValue, methodName, wrapperOnly, description};
        final Object[] old = OPTIONS.get(optionName);
        if (old != null) {
            if (asList(conf).subList(0, conf.length - 1).equals(asList(old).subList(0, conf.length - 1))) // don't compare description
                throw new IllegalStateException("Option " + optionName + " has a conflicting registration: " + Arrays.toString(old));
        }
        OPTIONS.put(optionName, conf);
        return optionName;
    }

    /**
     * Same as {@link #OPTION(String, String, String, boolean, String) OPTION(optionName, defaultValue, methodName, wrapperOnly, description)}.
     */
    protected static final String OPTION(String optionName, String defaultValue, String methodName, String description) {
        return OPTION(optionName, defaultValue, methodName, false, description);
    }

    private static boolean optionTakesArguments(String propertyName) {
        final String defaultValue = (String) OPTIONS.get(propertyName)[OPTION_DEFAULT];
        return !("false".equals(defaultValue) || "true".equals(defaultValue));
    }

    private static void processOptions() {
        for (Map.Entry<String, Object[]> entry : OPTIONS.entrySet()) {
            final String option = entry.getKey();
            final String defval = (String) entry.getValue()[OPTION_DEFAULT];
            if (getProperty0(option) == null && defval != null && !defval.equals("false")) // the last condition is for backwards compatibility
                setProperty(option, defval);
            else if (!optionTakesArguments(option) && "".equals(getProperty0(option)))
                setProperty(option, "true");
        }
    }

    private static void processCmdLineOptions(List<String> args, List<String> jvmArgs) {
        while (!args.isEmpty()) {
            if (!first(args).startsWith("-"))
                break;
            final String arg = args.remove(0);

            String optarg = null;
            if (arg.contains("="))
                optarg = getAfter(arg, '=');

            final String option = simpleToOption(getBefore(arg, '='));
            if (option == null)
                throw new IllegalArgumentException("Unrecognized option: " + arg);

            // -D wins over simple flags
            boolean overridden = false;
            for (String x : jvmArgs) {
                if (x.equals("-D" + option) || x.startsWith("-D" + option + "=")) {
                    overridden = true;
                    break;
                }
            }

            if (optarg == null)
                optarg = optionTakesArguments(option) ? args.remove(0) : "";

            if (!overridden)
                setProperty(option, optarg);
        }
        processOptions();
    }

    // visible for testing
    @SuppressWarnings("unchecked")
    static final boolean runActions(Capsule capsule, List<String> args) {
        verifyAgent(false);
        try {
            boolean found = false;
            for (Map.Entry<String, Object[]> entry : OPTIONS.entrySet()) {
                if (entry.getValue()[OPTION_METHOD] != null && systemPropertyEmptyOrNotFalse(entry.getKey())) {
                    if (!capsule.isWrapperCapsule() && (Boolean) entry.getValue()[OPTION_WRAPPER_ONLY])
                        throw new IllegalStateException("Action " + entry.getKey() + " is availbale for wrapper capsules only.");
                    final Method m = getMethod(capsule, (String) entry.getValue()[OPTION_METHOD], List.class);
                    m.invoke(capsule.cc.sup((Class<? extends Capsule>) m.getDeclaringClass()), args);
                    found = true;
                }
            }
            if (found)
                capsule.cleanup1();
            return found;
        } catch (InvocationTargetException e) {
            throw rethrow(e);
        } catch (ReflectiveOperationException e) {
            throw new AssertionError(e);
        }
    }

    private static String optionToSimple(String option) {
        if (PROP_HELP.equals(option))
            return "-h";
        if (PROP_INTROSPECT.equals(option))
            return "-i";
        if (PROP_VERSION.equals(option))
            return "-v";

        return "-" + camelCaseToDashed(option.substring(CAPSULE_PROP_PREFIX.length())).replace('.', '-');
    }

    private static String simpleToOption(String simple) {
        switch (simple) {
            case "-h": return PROP_HELP;
            case "-i": return PROP_INTROSPECT;
            case "-v": return PROP_VERSION;
        }
        for (String option : OPTIONS.keySet()) {
            if (simple.equals(optionToSimple(option)))
                return option;
        }
        return null;
    }

    private static String camelCaseToDashed(String camel) {
        return camel.replaceAll("([A-Z][a-z]+)", "-$1").toLowerCase();
    }

    private static boolean isCapsuleOption(String propertyName) {
        return propertyName.startsWith(CAPSULE_PROP_PREFIX); // OPTIONS.containsKey(propertyName);
    }
    //</editor-fold>
    //</editor-fold>

    private static Map<String, List<Path>> JAVA_HOMES; // an optimization trick (can be injected by CapsuleLauncher)
    private final Map<String, String> threads = new HashMap<>();

    // fields marked /*final*/ are effectively final after finalizeCapsule
    private /*final*/ Capsule oc;  // first in chain
    private /*final*/ Capsule cc;  // last in chain
    private /*final*/ Capsule sup; // previous in chain
    private /*final*/ Capsule _ct; // a temp var

    private final boolean wrapper;
    private final Manifest manifest;     // never null
    private /*final*/ Path jarFile;      // never null
    private /*final*/ String appId;      // null iff wrapper capsule wrapping a non-capsule JAR
    private /*final*/ String mode;
    private /*final*/ String nonCapsuleTarget;

    private Path javaHome;
    private String javaVersion;
    private Path cacheDir;
    private Path appDir;
    private Path writableAppCache;

    private boolean plainCache;
    private boolean cacheUpToDate;
    private FileLock appCacheLock;

    private int lifecycleStage;
    private String appArtifactMainClass;
    private List<String> jvmArgs_;
    private List<String> args_;
    private List<Path> tmpFiles = new ArrayList<>();
    private Process child;
    private boolean agentCalled;
    private MBeanServer origMBeanServer;
    private MBeanServerConnection jmxConnection;
    // Error reporting
    private static final ThreadLocal<String> contextType_ = new ThreadLocal<>();
    private static final ThreadLocal<String> contextKey_ = new ThreadLocal<>();
    private static final ThreadLocal<String> contextValue_ = new ThreadLocal<>();

    //
    private Object socket;
    private InetAddress address;
    private int port;
    private ObjectInput socketInput;
    private ObjectOutput socketOutput;

    //<editor-fold defaultstate="collapsed" desc="Constructors">
    /////////// Constructors ///////////////////////////////////
    /*
     * The constructors and methods in this section may be reflectively called by CapsuleLauncher
     */
    /**
     * Constructs a capsule.
     * <p>
     * This constructor is used by a caplet that will be listed in the manifest's {@code Main-Class} attribute.
     * <b>Caplets are encouraged to "override" the {@link #Capsule(Capsule) other constructor} so that they may be listed
     * in the {@code Caplets} attribute.</b>
     * <p>
     * This constructor or that of a subclass must not make use of any registered capsule options,
     * as they may not have been properly pre-processed yet.
     *
     * @param jarFile the path to the JAR file
     */
    @SuppressWarnings({"OverridableMethodCallInConstructor", "LeakingThisInConstructor"})
    protected Capsule(Path jarFile) {
        clearContext();
        Objects.requireNonNull(jarFile, "jarFile can't be null");

        this.oc = this;
        this.cc = this;
        this.sup = null;

        this.jarFile = toAbsolutePath(jarFile);

        final long start = System.nanoTime(); // can't use clock before log level is set
        try (JarInputStream jis = openJarInputStream(jarFile)) {
            this.manifest = jis.getManifest();
            if (manifest == null)
                throw new RuntimeException("Capsule " + jarFile + " does not have a manifest");
        } catch (IOException e) {
            throw new RuntimeException("Could not read JAR file " + jarFile, e);
        }

        setLogLevel(chooseLogLevel()); // temporary

        log(LOG_VERBOSE, "Jar: " + jarFile);
        log(LOG_VERBOSE, "Platform: " + PLATFORM);

        this.wrapper = isEmptyCapsule(); // must be done before loadCaplets, to init their wrapper field, but this implies the application must be specified in the manifest
        loadCaplets();

        setLogLevel(chooseLogLevel()); // temporary
        time("Load class " + this.getClass().getName(), START, start);
        time("Read JAR in constructor", start);

        if (!wrapper)
            finalizeCapsule();
        else if (isFactoryCapsule())
            this.jarFile = null; // an empty factory capsule is marked this way.
        clearContext();
    }

    /**
     * Caplets that will be listed on the manifest's {@code Caplets} attribute must use this constructor.
     * Caplets are required to have a constructor with the same signature as this constructor, and pass their arguments to up to this constructor.
     *
     * @param pred The capsule preceding this one in the chain (caplets must not access the passed capsule in their constructor).
     */
    @SuppressWarnings("LeakingThisInConstructor")
    protected Capsule(Capsule pred) {
        this.oc = pred.oc;
        this.cc = this;

        time("Load class " + this.getClass().getName(), START);
        clearContext();

        // insertAfter(pred);
        // copy final dields
        this.wrapper = pred.wrapper;
        this.manifest = pred.manifest;
        this.jarFile = pred.jarFile;
    }

    final Capsule setTarget(String target) {
        verifyCanCallSetTarget();
        final Path jar = isDependency(target) ? firstOrNull(resolve(lookup(target, ATTR_APP_ARTIFACT))) : toAbsolutePath(path(target));
        if (jar == null)
            throw new RuntimeException(target + " not found.");

        if (jar.equals(getJarFile())) // catch simple loops
            throw new RuntimeException("Capsule wrapping loop detected with capsule " + getJarFile());

        if (isFactoryCapsule()) {
            this.jarFile = jar;
            return this;
        }

        final Manifest man;
        boolean isCapsule = false;
        final long start = clock();
        try (JarInputStream jis = openJarInputStream(jar)) {
            man = jis.getManifest();
            if (man == null || man.getMainAttributes().getValue(ATTR_MAIN_CLASS) == null)
                throw new IllegalArgumentException(jar + " is not a capsule or an executable JAR");

            for (JarEntry entry; (entry = jis.getNextJarEntry()) != null;) {
                if (entry.getName().equals(Capsule.class.getName() + ".class")) {
                    isCapsule = true;
                    break;
                }
            }
        } catch (IOException e) {
            throw new RuntimeException("Could not read JAR file " + jar, e);
        }
        time("Read JAR in setTarget", start);

        if (!isCapsule)
            oc.nonCapsuleTarget = target;
        else {
            log(LOG_VERBOSE, "Wrapping capsule " + jar);
            insertAfter(loadTargetCapsule(cc.getClass().getClassLoader(), jar).cc);
        }
        finalizeCapsule();
        return this;
    }

    /**
     * Called once the capsule construction has been completed (after loading of wrapped capsule, if applicable).
     */
    protected void finalizeCapsule() {
        if ((_ct = getCallTarget(Capsule.class)) != null)
            _ct.finalizeCapsule();
        else
            finalizeCapsule0();
        clearContext();
    }

    private void finalizeCapsule0() {
        validateManifest(oc.manifest);
        setLogLevel(chooseLogLevel());
        oc.mode = chooseMode1();
        initAppId();

        if (getAppId() == null && !(hasAttribute(ATTR_APP_ARTIFACT) && !isDependency(getAttribute(ATTR_APP_ARTIFACT))))
            throw new IllegalArgumentException("Could not determine app ID. Capsule jar " + getJarFile() + " should have the " + ATTR_APP_NAME + " manifest attribute.");
    }

    private void verifyCanCallSetTarget() {
        if (getAppId() != null)
            throw new IllegalStateException("Capsule is finalized");
        if (!isEmptyCapsule())
            throw new IllegalStateException("Capsule " + getJarFile() + " isn't empty");
    }

    private void loadCaplets() {
        for (String caplet : getAttribute(ATTR_CAPLETS))
            loadCaplet(caplet, cc).insertAfter(cc);
    }

    private void initAppId() {
        if (oc.appId != null)
            return;
        log(LOG_VERBOSE, "Initializing app ID");
        final String name = getAppIdNoVer();
        if (name == null)
            return;
        final String version = getAttribute(ATTR_APP_VERSION);
        oc.appId = name + (version != null ? "_" + version : "");
        log(LOG_VERBOSE, "Initialized app ID: " + oc.appId);
    }

    protected final boolean isEmptyCapsule() {
        return !hasAttribute(ATTR_APP_ARTIFACT) && !hasAttribute(ATTR_APP_CLASS) && !hasAttribute(ATTR_SCRIPT);
    }

    private void setStage(int stage) {
        oc.lifecycleStage = stage;
    }

    private void verifyAtStage(int stage) {
        if (oc.lifecycleStage != stage)
            throw new IllegalStateException("This operation is not available at this stage in the capsule's lifecycle.");
    }

    protected final void verifyAfterStage(int stage) {
        if (oc.lifecycleStage <= stage)
            throw new IllegalStateException("This operation is not available at this stage in the capsule's lifecycle.");
    }

    // Called by tests
    private static void clearCaches() {
        jarEntriesCache.clear();
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Caplet Chain">
    /////////// Caplet Chain ///////////////////////////////////
    private Capsule loadCaplet(String caplet, Capsule pred) {
        log(LOG_VERBOSE, "Loading caplet: " + caplet);
        if (isDependency(caplet) || caplet.endsWith(".jar")) {
            final List<Path> jars = resolve(lookup(caplet, ATTR_CAPLETS));
            if (jars.size() != 1)
                throw new RuntimeException("The caplet " + caplet + " has transitive dependencies.");
            return newCapsule(first(jars), pred);
        } else
            return newCapsule(caplet, pred);
    }

    private void insertAfter(Capsule pred) {
        // private b/c this might be a security risk (wrapped capsule inserting a caplet after wrapper)
        // and also because it might be too powerful and prevent us from adopting a different caplet chain implementation
        log(LOG_VERBOSE, "Applying caplet " + this.getClass().getName());
        if (sup == pred)
            return;
        if (pred != null) {
            if (sup != null)
                throw new IllegalStateException("Caplet " + this + " is already in the chain (after " + sup + ")");
            if (!wrapper && pred.hasCaplet(this.getClass().getName())) {
                log(LOG_VERBOSE, "Caplet " + this.getClass().getName() + " has already been applied.");
                return;
            }

            this.sup = pred;
            this.oc = sup.oc;
            for (Capsule c = cc; c != this; c = c.sup)
                c.oc = oc;
            if (sup.cc == sup) { // I'm last
                for (Capsule c = sup; c != null; c = c.sup)
                    c.cc = cc;
            } else { // I'm in the middle
                throw new IllegalArgumentException("Caplet cannot be inserted in the middle of the hierarchy");
//                for (Capsule c = sup.cc; c != sup; c = c.sup) {
//                    if (c.sup == sup)
//                        c.sup = cc;
//                }
//                for (Capsule c = cc; c != this; c = c.sup)
//                    c.cc = sup.cc;
//                this.cc = sup.cc;
            }
        }
    }

    /**
     * Checks whether a caplet with the given class name is installed.
     */
    protected final boolean hasCaplet(String name) {
        for (Capsule c = cc; c != null; c = c.sup) {
            for (Class<?> cls = c.getClass(); cls != null; cls = cls.getSuperclass()) {
                if (name.equals(cls.getName()))
                    return true;
            }
        }
        return false;
    }

    /**
     * The first caplet in the caplet chain starting with the current one and going up (back) that is of the requested type.
     */
    protected final <T extends Capsule> T sup(Class<T> caplet) {
        for (Capsule c = this; c != null; c = c.sup) {
            if (caplet.isInstance(c))
                return caplet.cast(c);
        }
        return null;
    }

    /**
     * The first caplet in the caplet chain starting with the current one and going up (back) that is of the requested type.
     */
    protected final Capsule sup(String ClassName) {
        for (Capsule c = this; c != null; c = c.sup) {
            for (Class cls = c.getClass(); cls != null; cls = cls.getSuperclass()) {
                if (ClassName.equals(cls.getName()))
                    return c;
            }
        }
        return null;
    }

    // called by utils' Capsule
    final List<Class<? extends Capsule>> getCaplets() {
        final List<Class<? extends Capsule>> caplets = new ArrayList<>();
        for (Capsule c = cc; c != null; c = c.sup)
            caplets.add(c.getClass());
        Collections.reverse(caplets);
        return caplets;
    }

    protected final <T extends Capsule> T getCallTarget(Class<T> clazz) {
        /*
         * Here we're implementing both the "invokevirtual" and "invokespecial".
         * We want to somehow differentiate the case where the function is called directly -- and should, like invokevirtual, target cc, the
         * last caplet in the hieracrchy -- from the case where the function is called with super.foo -- and should, like invokevirtual,
         * target sup, the previous caplet in the hierarchy.
         */
        Capsule target = null;
        if ((sup == null || sup.sup(clazz) == null || this.jarFile != ((Capsule) sup.sup(clazz)).jarFile) && cc != this) { // the jarFile condition tests if this is the first caplet in a wrapper capsule
            final StackTraceElement[] st = new Throwable().getStackTrace();
            if (st == null || st.length < 3)
                throw new AssertionError("No debug information in Capsule class");

            final int c1 = 1;
            if (!st[c1].getClassName().equals(clazz.getName()))
                throw new RuntimeException("Illegal access. Method can only be called by the " + clazz.getName() + " class");

            int c2 = 2;
            while (isStream(st[c2].getClassName()))
                c2++;

            if (st[c1].getLineNumber() <= 0 || st[c2].getLineNumber() <= 0)
                throw new AssertionError("No debug information in Capsule class");

            // we return CC if the caller is also Capsule but not the same method (which would mean this is a sup.foo() call)
            if (!st[c2].getMethodName().equals(st[c1].getMethodName())
                || (st[c2].getClassName().equals(clazz.getName()) && Math.abs(st[c2].getLineNumber() - st[c1].getLineNumber()) > 3))
                target = cc;
        }
        if (target == null)
            target = sup;

        return target != null ? target.sup(clazz) : null;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Properties">
    /////////// Properties ///////////////////////////////////
    private boolean isWrapperOfNonCapsule() {
        return nonCapsuleTarget != null;
    }

    private boolean isFactoryCapsule() {
        if (!getClass().equals(Capsule.class) || !wrapper)
            return false;
        for (Object attr : manifest.getMainAttributes().keySet()) {
            if (ATTRIBS.containsKey(attr.toString()))
                return false;
        }
        for (Attributes atts : manifest.getEntries().values()) {
            for (Object attr : atts.keySet()) {
                if (ATTRIBS.containsKey(attr.toString()))
                    return false;
            }
        }
        log(LOG_DEBUG, "Factory (unchanged) capsule");
        return true;
    }

    /**
     * Whether or not this is an empty capsule
     */
    protected final boolean isWrapperCapsule() {
        for (Capsule c = cc; c != null; c = c.sup) {
            if (c.wrapper)
                return true;
        }
        return false;
    }

    /**
     * This capsule's current mode.
     */
    protected final String getMode() {
        return oc.mode;
    }

    /**
     * The OS platform.
     */
    protected final String getPlatform() {
        return PLATFORM;
    }

    /**
     * This capsule's JAR file.
     */
    protected final Path getJarFile() {
        return oc.jarFile;
    }

    /**
     * Returns the app's ID.
     */
    protected final String getAppId() {
        return oc.appId;
    }

    /**
     * Is this the Capsule instance running as an agent in the application?
     */
    public boolean isAgent() {
        return AGENT;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Capsule JAR">
    /////////// Capsule JAR ///////////////////////////////////
    private static Path findJarFile(Class<? extends Capsule> capsuleClass) {
        assert capsuleClass != null;
        final URL url = MY_CLASSLOADER.getResource(capsuleClass.getName().replace('.', '/') + ".class");
        if (url == null) // Could happen with embedded capsules
            throw new IllegalStateException("The " + capsuleClass + " class must be in a JAR file, but was not found");
        if (!"jar".equals(url.getProtocol()))
            throw new IllegalStateException("The " + capsuleClass + " class must be in a JAR file, but was loaded from: " + url);
        final String path = url.getPath();
        if (path == null) //  || !path.startsWith("file:")
            throw new IllegalStateException("The " + capsuleClass + " class must be in a local JAR file, but was loaded from: " + url);

        try {
            final URI jarUri = new URI(path.substring(0, path.indexOf('!')));
            return Paths.get(jarUri);
        } catch (URISyntaxException e) {
            throw new AssertionError(e);
        }
    }

    private static Path findOwnJarFile() {
        return findJarFile(Capsule.class);
    }

    private String toJarUrl(String relPath) {
        return "jar:file:" + getJarFile().toAbsolutePath() + "!/" + relPath;
    }

    private static boolean isExecutable(Path path) {
        if (!Files.isExecutable(path))
            return false;
        try (Reader reader = new InputStreamReader(Files.newInputStream(path), "UTF-8")) {
            int c = reader.read();
            if (c < 0 || (char) c != '#')
                return false;
            c = reader.read();
            if (c < 0 || (char) c != '!')
                return false;
            return true;
        } catch (IOException e) {
            throw rethrow(e);
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Main Operations">
    /////////// Main Operations ///////////////////////////////////
    void printVersion(List<String> args) {
        if (getAppId() != null) {
            STDOUT.println(LOG_PREFIX + "Application " + getAppId());
            if (hasAttribute(ATTR_APP_NAME))
                STDOUT.println(LOG_PREFIX + getAttribute(ATTR_APP_NAME));
            if (hasAttribute(ATTR_APP_VERSION))
                STDOUT.println(LOG_PREFIX + "Version: " + getAttribute(ATTR_APP_VERSION));
            for (String attr : asList(ATTR_IMPLEMENTATION_VENDOR, ATTR_IMPLEMENTATION_URL)) {
                if (getManifestAttribute(attr) != null)
                    STDOUT.println(LOG_PREFIX + getManifestAttribute(attr));
            }
        }
        STDOUT.println(LOG_PREFIX + "Capsule version " + VERSION);
    }

    void printModes(List<String> args) {
        verifyNonEmpty("Cannot print modes of a wrapper capsule.");
        STDOUT.println(LOG_PREFIX + "Application " + getAppId());
        STDOUT.println("Available modes:");
        final Set<String> modes = getModes();
        if (modes.isEmpty())
            STDOUT.println("Default mode only");
        else {
            for (String m : modes) {
                final String desc = getModeDescription(m);
                STDOUT.println("* " + m + (desc != null ? ": " + desc : ""));
            }
        }
    }

    void printJVMs(List<String> args) {
        final Map<String, List<Path>> jres = getJavaHomes();
        if (jres == null)
            println("No detected Java installations");
        else {
            STDOUT.println(LOG_PREFIX + "Detected Java installations:");
            for (Map.Entry<String, List<Path>> j : jres.entrySet()) {
                for (Path home : j.getValue())
                    STDOUT.println(j.getKey() + (isJDK(home) ? " (JDK)" : "") + (j.getKey().length() < 8 ? "\t\t" : "\t") + home);
            }
        }
        final Path jhome = getJavaHome();
        STDOUT.println(LOG_PREFIX + "selected " + (jhome != null ? jhome : (getProperty(PROP_JAVA_HOME) + " (current)")));
    }

    void mergeCapsules(List<String> args) {
        if (!isWrapperCapsule())
            throw new IllegalStateException("This is not a wrapper capsule");
        try {
            final Path outCapsule = path(getProperty(PROP_MERGE));
            final Path wr = cc.jarFile;
            final Path wd = oc.jarFile;
            log(LOG_QUIET, "Merging " + wr + (!Objects.deepEquals(wr, wd) ? " + " + wd : "") + " -> " + outCapsule);
            mergeCapsule(wr, wd, outCapsule);
        } catch (Exception e) {
            throw new RuntimeException("Capsule merge failed.", e);
        }
    }

    void printHelp(List<String> args) {
        printHelp(wrapper);
    }

    private static void printHelp(boolean simple) {
        // USAGE:
        final Path myJar = toFriendlyPath(findOwnJarFile());
        final boolean executable = isExecutable(myJar);

        final StringBuilder usage = new StringBuilder();
        if (!executable)
            usage.append("java ");
        if (simple) {
            if (!executable)
                usage.append("-jar ");
            usage.append(myJar).append(' ');
        }
        usage.append("<options> ");
        if (!simple && !executable)
            usage.append("-jar ");
        if (simple)
            usage.append("<path or Maven coords of application JAR/capsule>");
        else
            usage.append(myJar);
        STDERR.println("USAGE: " + usage);

        // ACTIONS AND OPTIONS:
        for (boolean actions : new boolean[]{true, false}) {
            STDERR.println("\n" + (actions ? "Actions:" : "Options:"));
            for (Map.Entry<String, Object[]> entry : OPTIONS.entrySet()) {
                if (entry.getValue()[OPTION_DESC] != null && (entry.getValue()[OPTION_METHOD] != null) == actions) {
                    if (!simple && (Boolean) entry.getValue()[OPTION_WRAPPER_ONLY])
                        continue;
                    final String option = entry.getKey();
                    final String defaultValue = (String) entry.getValue()[OPTION_DEFAULT];
                    if (simple && !optionTakesArguments(option) && defaultValue.equals("true"))
                        continue;
                    StringBuilder sb = new StringBuilder();
                    sb.append(simple ? optionToSimple(option) : option);

                    if (optionTakesArguments(option) || defaultValue.equals("true")) {
                        sb.append(simple ? ' ' : '=').append("<value>");
                        if (defaultValue != null)
                            sb.append(" (default: ").append(defaultValue).append(")");
                    }
                    sb.append(" - ").append(entry.getValue()[OPTION_DESC]);

                    STDERR.println("  " + sb);
                }
            }
        }

        // ATTRIBUTES:
        if (1 == 2) {
            STDERR.println("\nManifest Attributes:");
            for (Map.Entry<String, Object[]> entry : ATTRIBS.entrySet()) {
                if (entry.getValue()[ATTRIB_DESC] != null) {
                    final String attrib = entry.getKey();
                    final String defaultValue = toString(entry.getValue()[ATTRIB_DEFAULT]);
                    StringBuilder sb = new StringBuilder();
                    sb.append(attrib);
                    if (defaultValue != null)
                        sb.append(" (default: ").append(defaultValue).append(")");
                    sb.append(" - ").append(entry.getValue()[ATTRIB_DESC]);

                    STDERR.println("  " + sb);
                }
            }
        }
    }
    
    void introspect(List<String> args) {
        STDERR.println("Capsule " + VERSION);
        
        final List<Class<? extends Capsule>> caplets = getCaplets();
        STDERR.println("Caplets: ");
        if (caplets.isEmpty())
            STDERR.println("  NONE");
        else {
            for (Class<?> caplet : caplets) {
                StringBuilder sb = new StringBuilder();
                sb.append(caplet.getName());
                String version;
                sb.append((version = getClassVersion(caplet)) != null ? " " + version : "");
                STDERR.println("  " + sb);
            }
        }
        
        STDERR.println();
        
        STDERR.println("Attributes");
        for (Map.Entry<String, Object[]> entry : ATTRIBS.entrySet()) {
            final String attrib = entry.getKey();

            StringBuilder sb = new StringBuilder();
            sb.append(attrib);
            if (entry.getValue()[ATTRIB_DESC] != null)
                sb.append(" (").append(entry.getValue()[ATTRIB_DESC]).append(')');
            sb.append(": ");
            
            sb.append("\n\t");
            final Entry<String, ?> attr = attr(attrib);
            final Object value = getAttributeNoLookup(attr);
            sb.append(value);

            final Object defaultValue = getAttributeDefaultValue(attr);
            if (Objects.equals(value, defaultValue))
                sb.append(" (default)");

            STDERR.println("  " + sb);
        }
    }

    @SuppressWarnings("empty-statement")
    private int launch(List<String> args) throws IOException, InterruptedException {
        verifyAgent(false);
        setStage(STAGE_LAUNCH);
        verifyNonEmpty("Cannot launch a wrapper capsule.");
        final ProcessBuilder pb;

        final List<String> jvmArgs = ManagementFactory.getRuntimeMXBean().getInputArguments();
        pb = prepareForLaunch(jvmArgs, args);
        if (pb == null) { // can be null if prelaunch has been overridden by a subclass
            log(LOG_VERBOSE, "Nothing to run");
            return 0;
        }

        clearContext();

        time("Total", START);
        log(LOG_VERBOSE, join(pb.command(), " ") + (pb.directory() != null ? " (Running in " + pb.directory() + ")" : ""));

        clearContext();
        return launch(pb);
    }

    private void verifyNonEmpty(String message) {
        if (isEmptyCapsule())
            throw new IllegalArgumentException(message);
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Threads">
    /////////// Threads ///////////////////////////////////
    private Thread startThread(String name, String method) {
        if (threads.containsKey(name))
            throw new IllegalStateException("A thread by the name " + name + " has already been registered.");
        threads.put(name, method);
        final Thread t = new Thread(this, name);
        t.setDaemon(true);
        t.start();
        return t;
    }

    /**
     * @deprecated marked deprecated to exclude from javadoc
     */
    @Override
    public final void run() {
        final String threadName = Thread.currentThread().getName();
        try {
            final String methodName = threads.get(threadName);
            if (methodName != null) {
                try {
                    getMethod(Capsule.class, methodName).invoke(this);
                    return;
                } catch (ReflectiveOperationException e) {
                    throw rethrow(e);
                }
            }

            // shutdown hook
            cleanup1();
        } catch (Throwable e) {
            log(LOG_QUIET, "Exception on thread " + threadName + ": " + e.getMessage());
            printError(LOG_QUIET, e);
            throw rethrow(e);
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Launch">
    /////////// Launch ///////////////////////////////////
    // directly used by CapsuleLauncher
    final ProcessBuilder prepareForLaunch(List<String> jvmArgs, List<String> args) {
        verifyAgent(false);
        oc.jvmArgs_ = nullToEmpty(jvmArgs); // hack
        oc.args_ = nullToEmpty(jvmArgs);    // hack

        log(LOG_VERBOSE, "Launching app " + getAppId() + (getMode() != null ? " in mode " + getMode() : ""));
        final long start = clock();
        lookupAllDependencies();
        final ProcessBuilder pb = prelaunch(nullToEmpty(jvmArgs), nullToEmpty(args));
        time("prepareForLaunch", start);
        return pb;
    }

    /**
     * Launches the process defined by the given {@link ProcessBuilder}.
     *
     * @param pb the process builder
     * @return the process's exit value
     */
    protected int launch(ProcessBuilder pb) throws IOException, InterruptedException {
        return (_ct = unsafe(getCallTarget(Capsule.class))) != null ? _ct.launch(pb) : launch0(pb);
    }

    private int launch0(ProcessBuilder pb) throws IOException, InterruptedException {
        if (isTrampoline())
            STDOUT.println(trampolineString(pb));
        else {
            Runtime.getRuntime().addShutdownHook(new Thread(this, "cleanup"));

            overridePlatformMBeanServer();

            if (!isInheritIoBug())
                pb.inheritIO();

            oc.child = pb.start();
            oc.child = postlaunch(oc.child);
            if (oc.child == null)
                return 0;

            setStage(STAGE_LIFTOFF);
            final int pid = getPid(oc.child);
            if (pid > 0)
                System.setProperty(PROP_CAPSULE_APP_PID, Integer.toString(pid));

            if (isInheritIoBug())
                pipeIoStreams();
            if (oc.socket != null)
                startServer();
            liftoff();
            // receiveLoop();

            oc.child.waitFor();
        }

        return oc.child != null ? oc.child.exitValue() : 0;
    }

    private String trampolineString(ProcessBuilder pb) {
        if (hasAttribute(ATTR_ENV))
            throw new RuntimeException("Capsule cannot trampoline because manifest defines the " + ATTR_ENV + " attribute.");
        final List<String> cmdline = new ArrayList<>(pb.command());
        cmdline.remove("-D" + PROP_TRAMPOLINE);
        for (int i = 0; i < cmdline.size(); i++)
            cmdline.set(i, "\"" + cmdline.get(i) + "\"");
        return join(cmdline, " ");
    }

    private void cleanup1() {
        log(LOG_VERBOSE, "Cleanup");
        log(LOG_DEBUG, new Exception("Stack trace"));
        cleanup();
    }

    /**
     * Called when the capsule exits after a successful or failed attempt to launch the application.
     * If you override this method, you must make sure to call {@code super.cleanup()} even in the event of an abnormal termination
     * (i.e. when an exception is thrown). This method must not throw any exceptions. All exceptions origination by {@code cleanup}
     * must be wither ignored completely or printed to STDERR.
     */
    protected void cleanup() {
        if ((_ct = getCallTarget(Capsule.class)) != null)
            _ct.cleanup();
        else
            cleanup0();
    }

    private void cleanup0() {
        try {
            if (oc.child != null) {
                killChild();
                oc.child.waitFor();
            }
            oc.child = null;
        } catch (Exception t) {
            deshadow(t).printStackTrace(STDERR);
        }

        for (Path p : oc.tmpFiles) {
            try {
                delete(p);
            } catch (Exception t) {
                log(LOG_VERBOSE, t.getMessage());
            }
        }
        oc.tmpFiles.clear();
    }

    private void killChild() {
        if (isWindows()) {
            if (!send(MESSAGE_EXIT, 1))
                oc.child.destroy();
        } else
            oc.child.destroy();
    }

    private boolean isChildAlive() {
        final Process c = oc.child;
        return c != null && isAlive(c);
    }

    protected final Path addTempFile(Path p) {
        log(LOG_VERBOSE, "Creating temp file/dir " + p);
        oc.tmpFiles.add(p);
        return p;
    }

    private String chooseMode1() {
        String m = chooseMode();
        if (m != null && !hasMode(m))
            throw new IllegalArgumentException("Capsule " + getJarFile() + " does not have mode " + m);
        return m;
    }

    /**
     * Chooses this capsule's mode.
     * The mode is chosen during the preparations for launch (not at construction time).
     */
    protected String chooseMode() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.chooseMode() : chooseMode0();
    }

    private String chooseMode0() {
        return emptyToNull(getProperty(PROP_MODE));
    }

    /**
     * Returns a configured {@link ProcessBuilder} that is later used to launch the capsule.
     * The ProcessBuilder's IO redirection is left in its default settings.
     * Caplets may override this method to display a message prior to launch, or to configure the process's IO streams.
     * For more elaborate manipulation of the Capsule's launched process, consider overriding {@link #buildProcess() buildProcess}.
     *
     * @param jvmArgs the JVM arguments listed on the command line
     * @param args    the application command-line arguments
     * @return a configured {@code ProcessBuilder} (if {@code null}, the launch will be aborted).
     */
    protected ProcessBuilder prelaunch(List<String> jvmArgs, List<String> args) {
        return (_ct = unsafe(getCallTarget(Capsule.class))) != null ? _ct.prelaunch(jvmArgs, args) : prelaunch0(jvmArgs, args);
    }

    private ProcessBuilder prelaunch0(List<String> jvmArgs, List<String> args) {
        try {
            if (!isTrampoline() && getAttribute(ATTR_AGENT))
                prepareServer();
            final ProcessBuilder pb = buildProcess();
            buildEnvironmentVariables(pb);
            pb.command().addAll(buildArgs(args));
            cleanupCache(null);
            return pb;
        } catch (Throwable t) {
            cleanupCache(t);
            throw t;
        }
    }

    /**
     * Constructs a {@link ProcessBuilder} that is later used to launch the capsule.
     * The returned process builder should contain the command <i>minus</i> the application arguments (which are later constructed by
     * {@link #buildArgs(List) buildArgs} and appended to the command).<br>
     * While environment variables may be set at this stage, the environment is later configured by
     * {@link #buildEnvironmentVariables(Map) buildEnvironmentVariables}.
     * <p>
     * This implementation tries to create a process running a startup script, and, if one has not been set, constructs a Java process.
     * <p>
     * This method should be overridden to add new types of processes the capsule can launch (like, say, Python scripts).
     * If all you want is to configure the returned {@link ProcessBuilder}, for example to set IO stream redirection,
     * you should override {@link #prelaunch(List, List) prelaunch}.
     *
     * @return a {@code ProcessBuilder} (must never be {@code null}).
     */
    protected ProcessBuilder buildProcess() {
        return (_ct = unsafe(getCallTarget(Capsule.class))) != null ? _ct.buildProcess() : buildProcess0();
    }

    private ProcessBuilder buildProcess0() {
        if (oc.jvmArgs_ == null)
            throw new IllegalStateException("Capsule has not been prepared for launch!");

        final ProcessBuilder pb = new ProcessBuilder();
        if (!buildScriptProcess(pb))
            buildJavaProcess(pb, oc.jvmArgs_);
        return pb;
    }

    /**
     * Returns a list of command line arguments to pass to the application.
     *
     * @param args The command line arguments passed to the capsule at launch
     */
    protected List<String> buildArgs(List<String> args) {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.buildArgs(args) : buildArgs0(args);
    }

    private List<String> buildArgs0(List<String> args) {
        return expandArgs(getAttribute(ATTR_ARGS), args);
    }

    // visible for testing
    static List<String> expandArgs(List<String> args0, List<String> args) {
        final List<String> args1 = new ArrayList<String>();
        boolean expanded = false;
        for (String a : args0) {
            if (a.startsWith("$")) {
                if (a.equals("$*")) {
                    args1.addAll(args);
                    expanded = true;
                    continue;
                } else {
                    try {
                        final int i = Integer.parseInt(a.substring(1));
                        args1.add(args.get(i - 1));
                        expanded = true;
                        continue;
                    } catch (NumberFormatException e) {
                    }
                }
            }
            args1.add(a);
        }
        if (!expanded)
            args1.addAll(args);
        return args1;
    }

    private void buildEnvironmentVariables(ProcessBuilder pb) {
        Map<String, String> env = new HashMap<>(pb.environment());
        env = buildEnvironmentVariables(env);
        pb.environment().clear();
        pb.environment().putAll(env);
    }

    /**
     * Returns a map of environment variables (property-value pairs).
     *
     * @param env the current environment
     */
    protected Map<String, String> buildEnvironmentVariables(Map<String, String> env) {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.buildEnvironmentVariables(env) : buildEnvironmentVariables0(env);
    }

    private Map<String, String> buildEnvironmentVariables0(Map<String, String> env) {
        final Map<String, String> jarEnv = getAttribute(ATTR_ENV);
        for (Map.Entry<String, String> e : jarEnv.entrySet()) {
            boolean overwrite = false;
            String var = e.getKey();
            if (var.endsWith(":")) {
                overwrite = true;
                var = var.substring(0, var.length() - 1);
            }

            if (overwrite || !env.containsKey(var))
                env.put(var, e.getValue() != null ? e.getValue() : "");
        }
        if (getAppId() != null) {
            if (getAppDir() != null)
                env.put(VAR_CAPSULE_DIR, processOutgoingPath(getAppDir()));
            env.put(VAR_CAPSULE_JAR, processOutgoingPath(getJarFile()));
            env.put(VAR_CAPSULE_APP, getAppId());
        }
        return env;
    }

    private static boolean isTrampoline() {
        return systemPropertyEmptyOrTrue(PROP_TRAMPOLINE);
    }

    /**
     * Called after the application has been launched by the capsule.
     * If this method returns a process, capsule will publish its pid (by setting a system property that may be queried by jcmd), await
     * its termination, and exit, returning its exit value. If this method returns {@code null}, the capsule will exit immediately,
     * without waiting for the child process to terminate. This method is also allowed to never return.
     *
     * @param child the child process running the application
     */
    protected Process postlaunch(Process child) {
        return ((_ct = getCallTarget(Capsule.class)) != null) ? _ct.postlaunch(child) : postlaunch0(child);
    }

    private Process postlaunch0(Process child) {
        return child;
    }

    /**
     * Called after the application has been launched by the capsule and {@link #postlaunch(Process) postlauch} has returned a non-null process.
     */
    protected void liftoff() {
        if ((_ct = getCallTarget(Capsule.class)) != null)
            _ct.liftoff();
        else
            liftoff0();
    }

    private void liftoff0() {
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Agent">
    /////////// Agent ///////////////////////////////////
    private static void verifyAgent(boolean isAgent) {
        if (AGENT != isAgent)
            throw new IllegalStateException("This operation is only available when " + (isAgent ? "agent" : "non-agent"));
    }

    /**
     * Called on a capsule agent instance in the application process.
     */
    protected void agent(Instrumentation inst) {
        if (oc.agentCalled)
            return;
        oc.agentCalled = true;

        if (getProperty(PROP_ADDRESS) != null || getProperty(PROP_PORT) != null)
            startClient();
    }

    @SuppressWarnings("unchecked")
    private <T> T agentAttributes(Entry<String, T> attr, T value) {
        if (ATTR_AGENT == attr) // prevent infinite recursion
            return value;
        if (!getAttribute(ATTR_AGENT))
            return value;

        if (ATTR_JAVA_AGENTS == attr) {
            // add the capsule as an agent
            final Map<Object, String> agents = new LinkedHashMap<>(cast(ATTR_JAVA_AGENTS, value));
            Path ownJar = null;
            try {
                ownJar = findOwnJarFile();
            } catch (final IllegalStateException ignored) {
            }
            if (ownJar != null)
                agents.put(processOutgoingPath(ownJar), isWrapperCapsule() ? processOutgoingPath(getJarFile()) : "");
            return (T) agents;
        }

        if (ATTR_SYSTEM_PROPERTIES == attr) {
            if (oc.address != null) {
                final Map<String, String> props = new HashMap<>(cast(ATTR_SYSTEM_PROPERTIES, value));
                props.put(PROP_ADDRESS, oc.address.getHostAddress());
                props.put(PROP_PORT, Integer.toString(oc.port));
                props.put(PROP_LOG_LEVEL, Integer.toString(getLogLevel()));
                return (T) props;
            }
        }

        return value;
    }

    private void prepareServer() {
        try {
            log(LOG_VERBOSE, "Starting capsule server.");
            InetSocketAddress sa = getLocalAddress();
            final ServerSocket server = new ServerSocket(sa.getPort(), 5, sa.getAddress());
            sa = (InetSocketAddress) server.getLocalSocketAddress();
            oc.address = sa.getAddress();
            oc.port = sa.getPort();
            oc.socket = server;
            log(LOG_VERBOSE, "Binding capsule server at: " + oc.address.getHostAddress() + ":" + oc.port);
        } catch (IOException e) {
            throw rethrow(e);
        }
    }

    private void startServer() throws IOException {
        try (ServerSocket server = (ServerSocket) oc.socket) {
            server.setSoTimeout(SOCKET_TIMEOUT);
            log(LOG_VERBOSE, "Waiting for client to connect...");
            final Socket s = server.accept();
            openSocketStreams(s);
            oc.socket = s;
            log(LOG_VERBOSE, "Client connected");
        } catch (IOException e) {
            if (isChildAlive()) {
                log(LOG_QUIET, "Client connection failed.");
                printError(LOG_QUIET, e);
                closeComm();
            }
        }
    }

    private void startClient() {
        log(LOG_VERBOSE, "Starting capsule client: " + getProperty(PROP_ADDRESS) + ":" + getProperty(PROP_PORT));
        if (getProperty(PROP_ADDRESS) == null || getProperty(PROP_PORT) == null)
            throw new IllegalStateException("Comm channel not defined");
        try {
            oc.address = InetAddress.getByName(getProperty(PROP_ADDRESS));
            oc.port = Integer.valueOf(getProperty(PROP_PORT));
            final Socket s = new Socket();
            s.connect(new InetSocketAddress(oc.address, oc.port), SOCKET_TIMEOUT);
            openSocketStreams(s);
            oc.socket = s;
            log(LOG_VERBOSE, "Client connected,");
            startThread("capsule-comm", "receiveLoop");
        } catch (IOException e) {
            log(LOG_VERBOSE, "Client connection failed.");
            printError(LOG_VERBOSE, e);
            closeComm();
        }
    }

    private void openSocketStreams(Socket s) throws IOException {
        synchronized (oc) {
            try {
                s.setSoTimeout(SOCKET_TIMEOUT);
                oc.socketOutput = new ObjectOutputStream(s.getOutputStream());
                oc.socketOutput.flush();
                oc.socketInput = new ObjectInputStream(s.getInputStream());
                s.setSoTimeout(0);
            } catch (IOException e) {
                if (e instanceof SocketTimeoutException)
                    log(LOG_VERBOSE, "Socket timed out");
                close(s);
                throw e;
            }
        }
    }

    private void closeComm() {
        synchronized (oc) {
            log(LOG_VERBOSE, "Closing comm");
            if (oc.socket != null)
                close(oc.socket);
            oc.socket = null;
            oc.address = null;
            oc.port = 0;
            oc.socketOutput = null;
            oc.socketInput = null;
        }
    }

    @SuppressWarnings("empty-statement")
    private void receiveLoop() {
        try {
            while (receive())
                ;
        } catch (IOException e) {
            try {
                final Process p = child;
                if (p != null && !waitFor(p, 100))
                    printError(LOG_QUIET, e);
            } catch (InterruptedException ex) {
            }
        }
    }

    private boolean send(int message, Object payload) {
        if (!AGENT)
            verifyAfterStage(STAGE_LAUNCH);
        if (oc.socketOutput == null)
            return false;
        try {
            send0(message, payload);
            return true;
        } catch (IOException e) {
            log(LOG_VERBOSE, "Sending of message " + message + ": " + payload + " failed - " + e.getMessage());
            log(LOG_DEBUG, e);
            return false;
        }
    }

    private void send0(int message, Object payload) throws IOException {
        synchronized (oc) {
            if (oc.socketOutput == null)
                throw new IOException("comm channel not defined");
            log(LOG_VERBOSE, "Sending message " + message + " : " + payload);
            oc.socketOutput.writeInt(message);
            oc.socketOutput.writeObject(payload);
            oc.socketOutput.flush();
        }
    }

    private boolean receive() throws IOException {
        synchronized (oc) {
            if (!AGENT)
                verifyAfterStage(STAGE_LAUNCH);
            if (oc.socket == null)
                return false;
            try {
                final int message = oc.socketInput.readInt();
                final Object payload = oc.socketInput.readObject();
                log(LOG_VERBOSE, "Message received " + message + " : " + payload);
                receive(message, payload);
                return true;
            } catch (EOFException e) {
                log(LOG_VERBOSE, "Received EOF");
                log(LOG_VERBOSE, e);
                return false;
            } catch (ClassNotFoundException e) {
                throw new IOException(e);
            }
        }
    }

    private void receive(int message, Object payload) {
        switch (message) {
            case MESSAGE_EXIT:
                System.exit((Integer) payload);
                break;
            case MESSAGE_START_JMX:
                if (AGENT) {
                    final JMXServiceURL jmxurl = startJMXServer();
                    if (jmxurl != null)
                        send(MESSAGE_JMX_URL, jmxurl);
                }
                break;
            case MESSAGE_JMX_URL:
                if (!AGENT)
                    connectToJMX((JMXServiceURL) payload);
                break;
        }
    }

    /**
     * For internal use; subject to change/removal.
     *
     * @deprecated exclude from javadocs
     */
    protected InetSocketAddress getLocalAddress() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.getLocalAddress() : getLocalAddress0();
    }

    private InetSocketAddress getLocalAddress0() {
        return new InetSocketAddress(0);
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="App ID">
    /////////// App ID ///////////////////////////////////
    private String getAppIdNoVer() {
        String id = getAttribute(ATTR_APP_ID);
        if (isEmpty(id))
            id = getAttribute(ATTR_APP_NAME);
        if (id == null) {
            id = getAttribute(ATTR_APP_CLASS);
            if (id != null && hasModalAttribute(ATTR_APP_CLASS))
                throw new IllegalArgumentException("App ID-related attribute " + ATTR_APP_CLASS + " is defined in a modal section of the manifest. "
                                                   + " In this case, you must add the " + ATTR_APP_ID + " attribute to the manifest's main section.");
        }
        return id;
    }

    static String getAppArtifactId(String coords) {
        if (coords == null)
            return null;
        final String[] cs = coords.split(":");
        return cs[0] + "." + cs[1];
    }

    static String getAppArtifactVersion(String coords) {
        if (coords == null)
            return null;
        final String[] cs = coords.split(":");
        if (cs.length < 3)
            return null;
        return cs[2];
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Capsule Cache">
    /////////// Capsule Cache ///////////////////////////////////
    /**
     * For internal use; subject to change/removal.
     *
     * @deprecated exclude from javadocs
     */
    protected final Path getCacheDir() {
        if (oc.cacheDir == null) {
            Path cache = CACHE_DIR;
            if (cache != null) {
                cache = initCacheDir(cache);
            } else {
                final String cacheDirEnv = System.getenv(ENV_CACHE_DIR);
                if (cacheDirEnv != null) {
                    if (cacheDirEnv.equalsIgnoreCase(CACHE_NONE))
                        return null;
                    cache = initCacheDir(Paths.get(cacheDirEnv));
                    if (cache == null)
                        throw new RuntimeException("Could not initialize cache directory " + Paths.get(cacheDirEnv));
                } else {
                    final String name = getCacheName();
                    cache = initCacheDir(getCacheHome().resolve(name));
                    if (cache == null) {
                        try {
                            cache = addTempFile(Files.createTempDirectory(getTempDir(), "capsule-"));
                        } catch (IOException e) {
                            log(LOG_VERBOSE, "Could not create directory: " + cache + " -- " + e.getMessage());
                            cache = null;
                        }
                    }
                }
            }
            log(LOG_VERBOSE, "Cache directory: " + cache);
            oc.cacheDir = cache;
        }
        return oc.cacheDir;
    }

    private static String getCacheName() {
        final String cacheNameEnv = System.getenv(ENV_CACHE_NAME);
        final String cacheName = cacheNameEnv != null ? cacheNameEnv : CACHE_DEFAULT_NAME;
        return (isWindows() ? "" : ".") + cacheName;
    }

    private Path initCacheDir(Path cache) {
        try {
            if (!Files.exists(cache))
                Files.createDirectories(cache, getPermissions(getExistingAncestor(cache)));
            return cache;
        } catch (IOException e) {
            log(LOG_VERBOSE, "Could not create directory: " + cache + " -- " + e.getMessage());
            return null;
        }
    }

    private static Path getCacheHome() {
        final Path cacheHome;

        final Path userHome = Paths.get(getProperty(PROP_USER_HOME));
        if (!isWindows())
            cacheHome = userHome;
        else {
            Path localData;
            final String localAppData = getenv("LOCALAPPDATA");
            if (localAppData != null) {
                localData = Paths.get(localAppData);
                if (!Files.isDirectory(localData))
                    throw new RuntimeException("%LOCALAPPDATA% set to nonexistent directory " + localData);
            } else {
                localData = userHome.resolve(Paths.get("AppData", "Local"));
                if (!Files.isDirectory(localData))
                    localData = userHome.resolve(Paths.get("Local Settings", "Application Data"));
                if (!Files.isDirectory(localData))
                    throw new RuntimeException("%LOCALAPPDATA% is undefined, and neither "
                                               + userHome.resolve(Paths.get("AppData", "Local")) + " nor "
                                               + userHome.resolve(Paths.get("Local Settings", "Application Data")) + " have been found");
            }
            cacheHome = localData;
        }

        return cacheHome;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="App Cache">
    /////////// App Cache ///////////////////////////////////
    /**
     * This capsule's cache directory, or {@code null} if capsule has been configured not to extract, or the app cache dir hasn't been set up yet.
     */
    protected final Path getAppDir() {
        return oc.appDir;
    }

    private Path getOrCreateAppDir() {
        if (oc.appDir == null)
            oc.appDir = buildAppCacheDir();
        return oc.appDir;
    }

    /**
     * Returns this capsule's cache directory.
     * The difference between this method and {@link #getAppDir()} is that this method throws an exception if the app cache
     * cannot be retrieved, while {@link #getAppDir()} returns {@code null}.
     *
     * @throws IllegalStateException if the app cache hasn't been set up (yet).
     */
    protected final Path appDir() {
        final Path dir = getOrCreateAppDir();
        if (dir == null) {
            String message = "Capsule not extracted.";
            if (getAppId() == null) {
                if (isEmptyCapsule())
                    message += " This is a wrapper capsule and the wrapped capsule hasn't been set (yet)";
                else
                    message += " App ID has not been determined yet.";
            }
            throw new IllegalStateException(message);
        }
        return dir;
    }

    /**
     * Returns a writable directory that can be used to store files related to launching the capsule.
     */
    protected final Path getWritableAppCache() {
        if (oc.writableAppCache == null) {
            Path cache = getOrCreateAppDir();
            if (cache == null || !Files.isWritable(cache)) {
                try {
                    cache = addTempFile(Files.createTempDirectory(getTempDir(), "capsule-"));
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            oc.writableAppCache = cache;
        }
        return oc.writableAppCache;
    }

    private boolean hasWritableAppCache() {
        return oc.writableAppCache != null && !oc.writableAppCache.equals(getAppDir());
    }

    /**
     * Returns the path of the application cache (this is the directory where the capsule is extracted if necessary).
     */
    protected Path buildAppCacheDir() {
        return (_ct = unsafe(getCallTarget(Capsule.class))) != null ? _ct.buildAppCacheDir() : buildAppCacheDir0();
    }

    private Path buildAppCacheDir0() {
        initAppId();
        if (getAppId() == null)
            return null;

        oc.plainCache = true;
        try {
            final long start = clock();
            final Path dir = toAbsolutePath(getCacheDir().resolve(APP_CACHE_NAME).resolve(getAppId()));
            Files.createDirectories(dir, getPermissions(getExistingAncestor(dir)));

            oc.cacheUpToDate = isAppCacheUpToDate1(dir);
            if (!oc.cacheUpToDate) {
                resetAppCache(dir);
                extractCapsule(dir);
            } else
                log(LOG_VERBOSE, "App cache " + dir + " is up to date.");

            time("buildAppCacheDir", start);
            return dir;
        } catch (IOException e) {
            log(LOG_VERBOSE, "IOException while creating app cache: " + e.getMessage());
            log(LOG_VERBOSE, e);
            return null;
        }
    }

    private void resetAppCache(Path dir) throws IOException {
        try {
            log(LOG_DEBUG, "(Re)Creating cache for " + getJarFile() + " in " + dir.toAbsolutePath());
            final Path lockFile = dir.resolve(LOCK_FILE_NAME);
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(dir)) {
                for (Path f : ds) {
                    if (!lockFile.equals(f))
                        delete(f);
                }
            }
        } catch (IOException e) {
            throw new IOException("Exception while clearing app cache directory " + dir.toAbsolutePath(), e);
        }
    }

    private boolean isAppCacheUpToDate1(Path dir) throws IOException {
        boolean res = testAppCacheUpToDate(dir);
        if (!res) {
            lockAppCache(dir);
            res = testAppCacheUpToDate(dir);
            if (res)
                unlockAppCache(dir);
        }
        return res;
    }

    private boolean testAppCacheUpToDate(Path dir) throws IOException {
        if (systemPropertyEmptyOrTrue(PROP_RESET))
            return false;

        Path extractedFile = dir.resolve(TIMESTAMP_FILE_NAME);
        if (!Files.exists(extractedFile))
            return false;
        final FileTime jarTime = Files.getLastModifiedTime(getJarFile());
        final FileTime extractedTime = Files.getLastModifiedTime(extractedFile);
        final boolean fresh = extractedTime.compareTo(jarTime) >= 0;
        log(LOG_DEBUG, "JAR timestamp: " + jarTime + " Cache timestamp: " + extractedTime + " (" + (fresh ? "fresh" : "stale") + ")");
        return fresh;
    }

    private void extractCapsule(Path dir) throws IOException {
        try {
            log(LOG_VERBOSE, "Extracting " + getJarFile() + " to app cache directory " + dir.toAbsolutePath());
            log(LOG_DEBUG, new Exception("Stack trace"));
            extractJar(openJarInputStream(getJarFile()), dir);
        } catch (IOException e) {
            throw new IOException("Exception while extracting jar " + getJarFile() + " to app cache directory " + dir.toAbsolutePath(), e);
        }
    }

    private void cleanupCache(Throwable exception) {
        try {
            try {
                if (exception == null)
                    markCache();
            } finally {
                unlockAppCache();
            }
        } catch (IOException e) {
            throw rethrow(e);
        }
    }

    private void markCache() throws IOException {
        if (!oc.plainCache || oc.appDir == null || oc.cacheUpToDate)
            return;
        if (Files.isWritable(oc.appDir))
            Files.createFile(oc.appDir.resolve(TIMESTAMP_FILE_NAME));
    }

    private void lockAppCache(Path dir) throws IOException {
        final Path lockFile = addTempFile(dir.resolve(LOCK_FILE_NAME));
        log(LOG_VERBOSE, "Locking " + lockFile);
        final FileChannel c = FileChannel.open(lockFile, new HashSet<>(asList(StandardOpenOption.CREATE, StandardOpenOption.WRITE)), getPermissions(dir));

        if (this.appCacheLock != null) {
            // This shouldn't happen, but due to some other bug it's possible that the cache was locked and not released.
            // In this case, attempting to lock again would throw an OverlappingFileLockException and may obscure the real problem.
            log(LOG_QUIET, "Attempting to double lock (ignoring, but this is most likely a bug in CAPSULE)");
            c.close();
        } else {
            this.appCacheLock = c.lock();
        }
    }

    private void unlockAppCache(Path dir) throws IOException {
        if (appCacheLock != null) {
            log(LOG_VERBOSE, "Unlocking " + dir.resolve(LOCK_FILE_NAME));
            appCacheLock.release();
            appCacheLock.acquiredBy().close();
            appCacheLock = null;
        }
    }

    private void unlockAppCache() throws IOException {
        if (!oc.plainCache || oc.appDir == null)
            return;
        unlockAppCache(oc.appDir);
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Script Process">
    /////////// Script Process ///////////////////////////////////
    private boolean buildScriptProcess(ProcessBuilder pb) {
        final Object script = getAttribute(ATTR_SCRIPT);
        if (script == null)
            return false;

        setJavaHomeEnv(pb, getJavaHome());

        final List<Object> classPath = getAttribute(ATTR_APP_CLASS_PATH);
        resolveNativeDependencies();
        pb.environment().put(VAR_CLASSPATH, compileClassPath(resolve(classPath)));

        pb.command().add(processOutgoingPath(script));
        return true;
    }

    private Path setJavaHomeEnv(ProcessBuilder pb, Path javaHome) {
        if (javaHome == null)
            return null;
        pb.environment().put(VAR_JAVA_HOME, processOutgoingPath(javaHome));
        return javaHome;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Java Process">
    /////////// Java Process ///////////////////////////////////
    private boolean buildJavaProcess(ProcessBuilder pb, List<String> cmdLine) {
        final List<String> command = pb.command();

        command.add(processOutgoingPath(getJavaExecutable()));

        command.addAll(buildJVMArgs(cmdLine));

        addOption(command, "-Xbootclasspath:", compileClassPath(resolve(buildBootClassPath(cmdLine))));
        addOption(command, "-Xbootclasspath/p:", compileClassPath(resolve(getAttribute(ATTR_BOOT_CLASS_PATH_P))));
        addOption(command, "-Xbootclasspath/a:", compileClassPath(resolve(getAttribute(ATTR_BOOT_CLASS_PATH_A))));

        command.addAll(compileAgents("-javaagent:", buildAgents(true)));
        command.addAll(compileAgents("-agentpath:", buildAgents(false)));

        final List<Path> classPath = resolve(getAttribute(ATTR_APP_CLASS_PATH));

        final String mainClass = getMainClass(classPath);
        command.addAll(compileSystemProperties(buildSystemProperties(cmdLine))); // must be called after buildClassPath and all resolutions

        final String cpstr;
        if ((cpstr = compileClassPath(handleLongClasspath(classPath, mainClass.length(), command, oc.args_))) != null) {
            command.add("-classpath");
            command.add(cpstr);
        }

        command.add(mainClass);
        return true;
    }

    private void lookupAllDependencies() {
        final long start = clock();
        if (hasAttribute(ATTR_APP_ARTIFACT))
            lookup(getAttribute(ATTR_APP_ARTIFACT));
        for (Map.Entry<String, Object[]> attr : ATTRIBS.entrySet()) {
            if (hasFILE_T(attr.getValue()[ATTRIB_TYPE]))
                getAttribute(attr(attr.getKey()));
        }
        time("lookupAllDependencies", start);
    }

    /**
     * Returns the path to the executable that will be used to launch Java.
     * The default implementation uses the {@code capsule.java.cmd} property or the {@code JAVACMD} environment variable,
     * and if not set, returns the value of {@code getJavaExecutable(getJavaHome())}.
     */
    protected Path getJavaExecutable() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.getJavaExecutable() : getJavaExecutable0();
    }

    private Path getJavaExecutable0() {
        String javaCmd = emptyToNull(getProperty(PROP_CAPSULE_JAVA_CMD));
        if (javaCmd != null)
            return path(javaCmd);

        return getJavaExecutable(getJavaHome());
    }

    /**
     * Finds the path to the executable that will be used to launch Java within the given {@code javaHome}.
     */
    protected static final Path getJavaExecutable(Path javaHome) {
        return getJavaExecutable0(javaHome);
    }

    private static List<String> compileSystemProperties(Map<String, String> ps) {
        final List<String> command = new ArrayList<>();
        for (Map.Entry<String, String> entry : ps.entrySet())
            command.add("-D" + entry.getKey() + (entry.getValue() != null && !entry.getValue().isEmpty() ? "=" + entry.getValue() : ""));
        return command;
    }

    private String compileClassPath(List<Path> cp) {
        if (isEmpty(cp))
            return null;
        return join(cp, PATH_SEPARATOR);
    }

    private List<String> compileAgents(String clo, Map<Path, String> agents) {
        final List<String> command = new ArrayList<>();
        for (Map.Entry<Path, String> agent : nullToEmpty(agents).entrySet())
            command.add(clo + first(resolve(agent.getKey())) + (agent.getValue().isEmpty() ? "" : ("=" + agent.getValue())));
        return command;
    }

    private static void addOption(List<String> cmdLine, String prefix, String value) {
        if (value == null)
            return;
        cmdLine.add(prefix + value);
    }

    private List<Object> buildClassPath0(List<Object> classPath0) {
        final long start = clock();
        final List<Object> classPath = new ArrayList<>();

        // The caplets and capsule jars
        if (!isWrapperOfNonCapsule() && getAttribute(ATTR_CAPSULE_IN_CLASS_PATH))
            addCapsuleJars(classPath);

        if (hasAttribute(ATTR_APP_ARTIFACT)) {
            final String artifact = getAttribute(ATTR_APP_ARTIFACT);
            if (isGlob(artifact))
                throw new IllegalArgumentException("Glob pattern not allowed in " + ATTR_APP_ARTIFACT + " attribute.");
            final Object app = lookup((isWrapperOfNonCapsule() && !isDependency(artifact)) ? toAbsolutePath(path(artifact)).toString()
                    : sanitize(artifact), ATTR_APP_ARTIFACT);
            classPath.add(app);
        }

        addAllIfAbsent(classPath, classPath0);
        classPath.add(lookup("*.jar", ATTR_APP_CLASS_PATH));

        classPath.addAll(nullToEmpty(getAttribute(ATTR_DEPENDENCIES)));

        // The caplets and capsule jars
        if (!isWrapperOfNonCapsule() && isDeepEmpty(classPath))
            addCapsuleJars(classPath);

        // Remove duplicate JARs while preserving order
        final List<Object> ret = new ArrayList<>(new LinkedHashSet<>(classPath));

        time("buildClassPath", start);

        return ret;
    }

    private void addCapsuleJars(List<Object> classPath) {
        Capsule c = this.cc;
        do {
            Path p = null;
            try {
                p = findJarFile(c.getClass());
            } catch (final IllegalStateException ignored) {
            } // Ignore non-JARs
            if (p != null && !classPath.contains(p))
                classPath.add(p);
        } while ((c = sup) != null);

        classPath.add(getJarFile());
    }

    /**
     * Compiles and returns the application's boot classpath as a list of paths.
     */
    private List<?> buildBootClassPath(List<String> cmdLine) {
        String option = null;
        for (String o : cmdLine) {
            if (o.startsWith("-Xbootclasspath:"))
                option = o.substring("-Xbootclasspath:".length());
        }
        return option != null ? toPath(asList(option.split(PATH_SEPARATOR))) : getAttribute(ATTR_BOOT_CLASS_PATH);
    }

    private Map<String, String> buildSystemProperties(List<String> cmdLine) {
        final Map<String, String> systemProperties = buildSystemProperties();

        // command line overrides everything
        for (String option : cmdLine) {
            if (option.startsWith("-D") && (!isCapsuleOption(option.substring(2)) || getAttribute(ATTR_AGENT)))
                addSystemProperty(option.substring(2), systemProperties);
        }

        return systemProperties;
    }

    private Map<String, String> buildSystemProperties() {
        final Map<String, String> systemProperties = new HashMap<>();

        // attribute
        for (Map.Entry<String, String> pv : getAttribute(ATTR_SYSTEM_PROPERTIES).entrySet())
            systemProperties.put(pv.getKey(), pv.getValue());

        // library path
        final List<Path> libraryPath = buildNativeLibraryPath();
        systemProperties.put(PROP_JAVA_LIBRARY_PATH, compileClassPath(libraryPath));

        // security manager
        if (hasAttribute(ATTR_SECURITY_POLICY) || hasAttribute(ATTR_SECURITY_POLICY_A)) {
            systemProperties.put(PROP_JAVA_SECURITY_MANAGER, "");
            if (hasAttribute(ATTR_SECURITY_POLICY_A))
                systemProperties.put(PROP_JAVA_SECURITY_POLICY, toJarUrl(getAttribute(ATTR_SECURITY_POLICY_A)));
            if (hasAttribute(ATTR_SECURITY_POLICY))
                systemProperties.put(PROP_JAVA_SECURITY_POLICY, "=" + toJarUrl(getAttribute(ATTR_SECURITY_POLICY)));
        }
        if (hasAttribute(ATTR_SECURITY_MANAGER))
            systemProperties.put(PROP_JAVA_SECURITY_MANAGER, getAttribute(ATTR_SECURITY_MANAGER));

        // Capsule properties (must come last b/c of getAppDir)
        if (getAppId() != null) {
            if (getAppDir() != null)
                systemProperties.put(PROP_CAPSULE_DIR, processOutgoingPath(getAppDir()));
            systemProperties.put(PROP_CAPSULE_JAR, processOutgoingPath(getJarFile()));
            systemProperties.put(PROP_CAPSULE_APP, getAppId());
        }

        return systemProperties;
    }

    private static void addSystemProperty(String p, Map<String, String> ps) {
        try {
            String name = getBefore(p, '=');
            String value = getAfter(p, '=');
            ps.put(name, value);
        } catch (IllegalArgumentException e) {
            throw new IllegalArgumentException("Illegal system property definition: " + p);
        }
    }

    //<editor-fold desc="Native Dependencies">
    /////////// Native Dependencies ///////////////////////////////////
    private List<Path> buildNativeLibraryPath() {
        final List<Path> libraryPath = new ArrayList<>(getPlatformNativeLibraryPath());

        resolveNativeDependencies();
        libraryPath.addAll(0, resolve(getAttribute(ATTR_LIBRARY_PATH_P)));
        libraryPath.addAll(resolve(getAttribute(ATTR_LIBRARY_PATH_A)));
        if (!listJar(getJarFile(), "*." + getNativeLibExtension(), true).isEmpty())
            appDir();
        if (getAppDir() != null)
            libraryPath.add(getAppDir());
        if (hasWritableAppCache())
            libraryPath.add(getWritableAppCache());
        return libraryPath;
    }

    /**
     * Returns the default native library path for the Java platform the application uses.
     */
    protected List<Path> getPlatformNativeLibraryPath() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.getPlatformNativeLibraryPath() : getPlatformNativeLibraryPath0();
    }

    private List<Path> getPlatformNativeLibraryPath0() {
        // WARNING: this assumes the platform running the app (say a different Java home), has the same java.library.path.
        final List<String> ps = split(getProperty(PROP_JAVA_LIBRARY_PATH), PATH_SEPARATOR);
        ps.remove(".");
        return toPath(ps);
    }

    private void resolveNativeDependencies() {
        resolve(getAttribute(ATTR_NATIVE_DEPENDENCIES).keySet());
    }
    //</editor-fold>

    private List<String> buildJVMArgs(List<String> cmdLine) {
        final Map<String, String> jvmArgs = new LinkedHashMap<>();

        for (String option : buildJVMArgs())
            addJvmArg(option, jvmArgs);

        for (String option : nullToEmpty(parseCommandLineArguments(getProperty(PROP_JVM_ARGS))))
            addJvmArg(option, jvmArgs);

        // command line overrides everything
        for (String option : cmdLine) {
            if (!option.startsWith("-D") && !option.startsWith("-Xbootclasspath:"))
                addJvmArg(option, jvmArgs);
        }
        return new ArrayList<String>(jvmArgs.values());
    }

    private List<String> buildJVMArgs() {
        final Map<String, String> jvmArgs = new LinkedHashMap<>();

        for (String a : getAttribute(ATTR_JVM_ARGS)) {
            a = a.trim();
            if (!a.isEmpty() && !a.startsWith("-Xbootclasspath:") && !a.startsWith("-javaagent:"))
                addJvmArg(toNativePath(expand(a)), jvmArgs);
        }

        return new ArrayList<String>(jvmArgs.values());
    }

    private static void addJvmArg(String a, Map<String, String> args) {
        args.put(getJvmArgKey(a), a);
    }

    private static String getJvmArgKey(String a) {
        if (a.equals("-client") || a.equals("-server"))
            return "compiler";
        if (a.equals("-enablesystemassertions") || a.equals("-esa")
            || a.equals("-disablesystemassertions") || a.equals("-dsa"))
            return "systemassertions";
        if (a.equals("-jre-restrict-search") || a.equals("-no-jre-restrict-search"))
            return "-jre-restrict-search";
        if (a.startsWith("-Xloggc:"))
            return "-Xloggc";
        if (a.startsWith("-Xss"))
            return "-Xss";
        if (a.startsWith("-Xmx"))
            return "-Xmx";
        if (a.startsWith("-Xms"))
            return "-Xms";
        if (a.startsWith("-XX:+") || a.startsWith("-XX:-"))
            return "-XX:" + a.substring("-XX:+".length());
        if (a.contains("="))
            return a.substring(0, a.indexOf('='));
        return a;
    }

    private Map<Path, String> buildAgents(boolean java) {
        final long start = clock();
        final Map<Object, String> agents0 = getAttribute(java ? ATTR_JAVA_AGENTS : ATTR_NATIVE_AGENTS);
        final Map<Path, String> agents = new LinkedHashMap<>(agents0.size());
        for (Map.Entry<Object, String> agent : agents0.entrySet()) {
            final Object agentName = agent.getKey();
            final String agentOptions = agent.getValue();
            final Path agentPath = first(resolve(agentName));
            agents.put(agentPath, ((agentOptions != null && !agentOptions.isEmpty()) ? agentOptions : ""));
        }
        time("buildAgents (" + (java ? "java" : "native") + ")", start);
        return emptyToNull(agents);
    }

    private String getMainClass(List<Path> classPath) {
        log(LOG_DEBUG, "getMainClass: " + classPath);
        String mainClass = getAttribute(ATTR_APP_CLASS);
        if (mainClass == null && hasAttribute(ATTR_APP_ARTIFACT))
            mainClass = oc.appArtifactMainClass;
        if (mainClass == null)
            throw new RuntimeException("Jar " + first(classPath).toAbsolutePath() + " does not have a main class defined in the manifest.");
        return mainClass;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Get Java Home">
    /////////// Get Java Home ///////////////////////////////////
    /**
     * The path to the Java installation this capsule's app will use.
     */
    protected final Path getJavaHome() {
        if (oc.javaHome == null) {
            Entry<String, Path> jhome = chooseJavaHome();
            if (jhome == null)
                jhome = entry(getProperty(PROP_JAVA_VERSION), Paths.get(getProperty(PROP_JAVA_HOME)));
            oc.javaVersion = jhome.getKey();
            oc.javaHome = jhome.getValue();
            log(LOG_VERBOSE, "Using JVM: " + oc.javaHome);
        }
        return oc.javaHome;
    }

    /**
     * Chooses which Java installation to use for running the app.
     *
     * @return the path of the Java installation to use for launching the app and its version, or {@code null} if the current JVM is to be used.
     */
    protected Entry<String, Path> chooseJavaHome() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.chooseJavaHome() : chooseJavaHome0();
    }

    private Entry<String, Path> chooseJavaHome0() {
        final long start = clock();
        final String propJHome = emptyToNull(getProperty(PROP_CAPSULE_JAVA_HOME));
        Entry<String, Path> jhome = null;
        if (!"current".equals(propJHome)) {
            jhome = propJHome != null ? entry(getJavaVersion(Paths.get(propJHome)), Paths.get(propJHome)) : null;
            if (jhome == null && !isMatchingJavaVersion(getProperty(PROP_JAVA_VERSION), isJDK(Paths.get(getProperty(PROP_JAVA_HOME))))) {
                final boolean jdk = getAttribute(ATTR_JDK_REQUIRED);

                jhome = findJavaHome(jdk);
                if (isLogging(LOG_VERBOSE))
                    log(LOG_VERBOSE, "Finding JVM: " + ((System.nanoTime() - start) / 1_000_000) + "ms");

                if (jhome == null) {
                    throw new RuntimeException("Could not find Java installation for requested version "
                                               + '[' + "Min. Java version: " + getAttribute(ATTR_MIN_JAVA_VERSION)
                                               + " JavaVersion: " + getAttribute(ATTR_JAVA_VERSION)
                                               + " Min. update version: " + getAttribute(ATTR_MIN_UPDATE_VERSION) + ']'
                                               + " (JDK required: " + jdk + ")"
                                               + ". You can override the used Java version with the -D" + PROP_CAPSULE_JAVA_HOME + " flag.");
                }
            }
        }
        time("chooseJavaHome", start);
        return jhome;
    }

    private Entry<String, Path> findJavaHome(boolean jdk) {
        Map<String, List<Path>> homes = nullToEmpty(getJavaHomes());
        Path bestPath = null;
        String bestVersion = null;
        for (Map.Entry<String, List<Path>> e : homes.entrySet()) {
            for (Path home : e.getValue()) {
                final String v = e.getKey();
                log(LOG_DEBUG, "Trying JVM: " + e.getValue() + " (version " + v + ")");
                if (isMatchingJavaVersion(v, isJDK(home))) {
                    log(LOG_DEBUG, "JVM " + e.getValue() + " (version " + v + ") matches");
                    if (bestVersion == null || compareVersions(v, bestVersion) > 0) {
                        log(LOG_DEBUG, "JVM " + e.getValue() + " (version " + v + ") is best so far");
                        bestVersion = v;
                        bestPath = home;
                    }
                }
            }
        }
        return bestVersion != null ? entry(bestVersion, bestPath) : null;
    }

    private boolean isMatchingJavaVersion(String javaVersion, boolean jdk) {
        final boolean jdkRequired = getAttribute(ATTR_JDK_REQUIRED);

        if (jdkRequired && !jdk) {
            log(LOG_DEBUG, "Java version " + javaVersion + " fails to match because JDK required and this is not a JDK");
            return false;
        }
        if (hasAttribute(ATTR_MIN_JAVA_VERSION) && compareVersions(javaVersion, getAttribute(ATTR_MIN_JAVA_VERSION)) < 0) {
            log(LOG_DEBUG, "Java version " + javaVersion + " fails to match due to " + ATTR_MIN_JAVA_VERSION + ": " + getAttribute(ATTR_MIN_JAVA_VERSION));
            return false;
        }
        if (hasAttribute(ATTR_JAVA_VERSION) && compareVersions(javaVersion, shortJavaVersion(getAttribute(ATTR_JAVA_VERSION)), 3) > 0) {
            log(LOG_DEBUG, "Java version " + javaVersion + " fails to match due to " + name(ATTR_JAVA_VERSION) + ": " + getAttribute(ATTR_JAVA_VERSION));
            return false;
        }
        if (getMinUpdateFor(javaVersion) > parseJavaVersion(javaVersion)[3]) {
            log(LOG_DEBUG, "Java version " + javaVersion + " fails to match due to " + name(ATTR_MIN_UPDATE_VERSION) + ": " + getAttribute(ATTR_MIN_UPDATE_VERSION) + " (" + getMinUpdateFor(javaVersion) + ")");
            return false;
        }
        log(LOG_DEBUG, "Java version " + javaVersion + " matches");
        return true;
    }

    private int getMinUpdateFor(String version) {
        final Map<String, String> m = getAttribute(ATTR_MIN_UPDATE_VERSION);
        final int[] ver = parseJavaVersion(version);
        for (Map.Entry<String, String> entry : m.entrySet()) {
            if (equals(ver, toInt(shortJavaVersion(entry.getKey()).split(SEPARATOR_DOT)), 3))
                return Integer.parseInt(entry.getValue());
        }
        return 0;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Attributes">
    /////////// Attributes ///////////////////////////////////
    @SuppressWarnings("unchecked")
    private <T> T attribute0(Entry<String, T> attr) {
        T value;

        if (ATTR_APP_ID == attr) {
            String id = attribute00(ATTR_APP_ID);
            if (id == null && getManifestAttribute(ATTR_IMPLEMENTATION_TITLE) != null)
                id = getManifestAttribute(ATTR_IMPLEMENTATION_TITLE);
            if (id == null && hasAttribute(ATTR_APP_ARTIFACT) && isDependency(getAttribute(ATTR_APP_ARTIFACT)))
                id = getAppArtifactId(getAttribute(ATTR_APP_ARTIFACT));
            value = (T) id;
        } else if (ATTR_APP_ARTIFACT == attr) {
            String artifact = attribute00(ATTR_APP_ARTIFACT);
            if (artifact == null && oc.nonCapsuleTarget != null)
                artifact = oc.nonCapsuleTarget;
            value = (T) artifact;
        } else if (ATTR_APP_NAME == attr) {
            String name = attribute00(ATTR_APP_NAME);
            if (name == null)
                name = getManifestAttribute(ATTR_IMPLEMENTATION_TITLE);
            value = (T) name;
        } else if (ATTR_APP_VERSION == attr) {
            String ver = attribute00(ATTR_APP_VERSION);
            if (ver == null && getManifestAttribute(ATTR_IMPLEMENTATION_VERSION) != null)
                ver = getManifestAttribute(ATTR_IMPLEMENTATION_VERSION);
            if (ver == null && hasAttribute(ATTR_APP_ARTIFACT) && isDependency(getAttribute(ATTR_APP_ARTIFACT)))
                ver = getAppArtifactVersion(getAttribute(ATTR_APP_ARTIFACT));
            value = (T) ver;
        } else if (ATTR_APP_CLASS_PATH == attr) {
            value = (T) buildClassPath0(attribute00(ATTR_APP_CLASS_PATH));
        } else
            value = attribute00(attr);

        // various modifications:
        value = windowsAttributes(attr, value);
        value = agentAttributes(attr, value);

        return value;
    }

    /*
     * The methods in this section are the only ones accessing the manifest. Therefore other means of
     * setting attributes can be added by changing these methods alone.
     */
    /**
     * Registers a manifest attribute. Must be called during the caplet's static initialization.
     *
     * @param attrName     the attribute's name
     * @param type         the attribute's type, obtained by calling one (or a combination) of the "type" methods:
     *                     {@link #T_STRING() T_STRING}, {@link #T_BOOL() T_BOOL}, {@link #T_LONG() T_LONG}, {@link #T_DOUBLE() T_DOUBLE},
     *                     {@link #T_LIST(Object) T_LIST}, {@link #T_MAP(Object, Object, Object) T_MAP}, {@link #T_SET(Object) T_SET}
     * @param defaultValue the attribute's default value, or {@code null} for none; a {@code null} value for collection or map types will be transformed into the type's empty value (i.e. empty list, empty map, etc.)
     * @param allowModal   whether the attribute is modal (i.e. can be specified per mode); if {@code false}, then the attribute is only allowed in the manifest's main section.
     * @param description  a description of the attribute
     * @return the attribute's name
     */
    protected static final <T> Entry<String, T> ATTRIBUTE(String attrName, T type, T defaultValue, boolean allowModal, String description) {
        if (!isValidType(type))
            throw new IllegalArgumentException("Type " + type + " is not supported for attributes");
        final Object[] conf = new Object[]{type, defaultValue, allowModal, description};
        final Object[] old = ATTRIBS.get(attrName);
        if (old != null) {
            if (asList(conf).subList(0, conf.length - 1).equals(asList(old).subList(0, conf.length - 1))) // don't compare description
                throw new IllegalStateException("Attribute " + attrName + " has a conflicting registration: " + Arrays.toString(old));
        }
        ATTRIBS.put(attrName, conf);
        return attr(attrName);
    }

    private static <T> Entry<String, T> attr(String name) {
        return entry(name, null);
    }

    /**
     * Returns the value of the given manifest attribute with consideration to the capsule's mode.
     * If the attribute is not defined, its default value will be returned
     * (if set with {@link #ATTRIBUTE(String, Object, Object, boolean, String) ATTRIBUTE()}).
     * <p>
     * Note that caplets may manipulate the value this method returns by overriding {@link #attribute(Map.Entry) }.
     *
     * @param attr the attribute
     * @return the value of the attribute.
     */
    protected final <T> T getAttribute(Entry<String, T> attr) {
        try {
            T value = getAttributeNoLookup(attr);
            if (hasFILE_T(type(attr))) {
                value = lookupInAttribute(value, attr);
                setContext("attribute", name(attr), value);
            }
            return value;
        } catch (Exception e) {
            throw new RuntimeException("Exception while getting attribute " + name(attr), e);
        }
    }

    /**
     * Returns the default value of the given manifest attribute.
     *
     * @param attr the attribute
     * @return the default value of the attribute.
     */
    protected final <T> T getAttributeNoLookup(Entry<String, T> attr) {
        setContext("attribute", name(attr), null);
        if (name(ATTR_CAPLETS).equals(name(attr)))
            return attribute0(attr);
        try {
            T value = cc.attribute(attr);
            setContext("attribute", name(attr), value);
            return value;
        } catch (Exception e) {
            throw new RuntimeException("Exception while getting attribute " + name(attr), e);
        }
    }
    
    protected final <T> T getAttributeDefaultValue(Entry<String, T> attr) {
        final Object[] conf = ATTRIBS.get(name(attr));
        final T type = type(attr);
        return defaultValue(type, (T) (conf != null ? conf[ATTRIB_DEFAULT] : null));
    }

    @SuppressWarnings("unchecked")
    private static <T> T cast(Entry<String, T> attr, Object value) {
        return (T) value;
    }

    /**
     * Returns an attribute's name.
     */
    protected final String name(Entry<String, ?> attribute) {
        if (attribute == null)
            return null;
        return attribute.getKey();
    }

    private <T> T type(Entry<String, T> attribute) {
        final Object[] conf = ATTRIBS.get(name(attribute));
        return (T) (conf != null ? conf[ATTRIB_TYPE] : T_STRING());
    }

    private static boolean isLegalModeName(String name) {
        return !name.contains("/") && !name.endsWith(".class") && !name.endsWith(".jar")
               && !isJavaVersionSpecific(name) && !isOsSpecific(name);
    }

    private void validateManifest(Manifest manifest) {
        final String mainClass = manifest.getMainAttributes().getValue(ATTR_MAIN_CLASS);
//        if (mainClass != null && !mainClass.equals(manifest.getMainAttributes().getValue(ATTR_PREMAIN_CLASS)))
//            throw new IllegalStateException("Capsule manifest must specify " + mainClass
//                    + " in the " + ATTR_PREMAIN_CLASS + " attribute.");

        if (manifest.getMainAttributes().getValue(ATTR_CLASS_PATH) != null)
            throw new IllegalStateException("Capsule manifest contains a " + ATTR_CLASS_PATH + " attribute."
                                            + " Use " + ATTR_APP_CLASS_PATH + " and/or " + ATTR_DEPENDENCIES + " instead.");
        validateNonModalAttributes(manifest);

        if (!hasAttribute(ATTR_APP_NAME) && hasModalAttribute(ATTR_APP_ARTIFACT))
            throw new IllegalArgumentException("App ID-related attribute " + ATTR_APP_ARTIFACT + " is defined in a modal section of the manifest. "
                                               + " In this case, you must add the " + ATTR_APP_NAME + " attribute to the manifest's main section.");

        // validate section case-insensitivity
        final Set<String> sectionsLowercase = new HashSet<>();
        for (String section : manifest.getEntries().keySet()) {
            if (!sectionsLowercase.add(section.toLowerCase()))
                throw new IllegalArgumentException("Manifest in JAR " + jarFile + " contains a case-insensitive duplicate of section " + section);
        }
    }

    private void validateNonModalAttributes(Manifest manifest) {
        for (Map.Entry<String, Attributes> entry : manifest.getEntries().entrySet()) {
            for (Object attr : entry.getValue().keySet()) {
                if (!allowsModal(attr.toString()))
                    throw new IllegalStateException("Manifest section " + entry.getKey() + " contains non-modal attribute " + attr);
            }
        }
    }

    private boolean hasModalAttribute(Entry<String, ?> attr) {
        final Attributes.Name key = new Attributes.Name(name(attr));
        for (Map.Entry<String, Attributes> entry : oc.manifest.getEntries().entrySet()) {
            if (entry.getValue().containsKey(key))
                return true;
        }
        return false;
    }

    private boolean hasMode(String mode) {
        if (!isLegalModeName(mode))
            throw new IllegalArgumentException(mode + " is an illegal mode name");
        if (oc.manifest.getAttributes(mode) != null)
            return true;
        return false;
    }

    /**
     * Returns the names of all modes defined in this capsule's manifest.
     */
    protected final Set<String> getModes() {
        final Set<String> modes = new HashSet<>();
        for (Map.Entry<String, Attributes> entry : oc.manifest.getEntries().entrySet()) {
            if (isLegalModeName(entry.getKey()) && !isDigest(entry.getValue()))
                modes.add(entry.getKey());
        }
        return unmodifiableSet(modes);
    }

    @SuppressWarnings("unchecked")
    private String getManifestAttribute(String attr) {
        return oc.manifest.getMainAttributes().getValue(attr);
    }

    /**
     * Returns the description of the given mode.
     */
    protected final String getModeDescription(String mode) {
        if (!isLegalModeName(mode))
            throw new IllegalArgumentException(mode + " is an illegal mode name");
        if (oc.manifest != null && oc.manifest.getAttributes(mode) != null)
            return oc.manifest.getAttributes(mode).getValue(name(ATTR_MODE_DESC));
        return null;
    }

    private static boolean isDigest(Attributes attrs) {
        for (Object name : attrs.keySet()) {
            if (!name.toString().toLowerCase().endsWith("-digest") && !name.toString().equalsIgnoreCase("Magic"))
                return false;
        }
        return true;
    }

    private static boolean isOsSpecific(String section) {
        section = section.toLowerCase();
        if (PLATFORMS.contains(section))
            return true;
        for (String os : PLATFORMS) {
            if (section.endsWith("-" + os))
                return true;
        }
        return false;
    }

    private static final Pattern PAT_JAVA_SPECIFIC_SECTION = Pattern.compile("\\A(.+-|)java-[0-9]+\\z");

    private static boolean isJavaVersionSpecific(String section) {
        return PAT_JAVA_SPECIFIC_SECTION.matcher(section.toLowerCase()).find();
    }

    /**
     * CAPLET OVERRIDE ONLY: Returns the value of the given capsule attribute with consideration to the capsule's mode.
     * Caplets may override this method to manipulate capsule attributes. This method must not be called directly except
     * as {@code super.attribute(attr)} calls in the caplet's implementation of this method.
     * <p>
     * The default implementation parses and returns the relevant manifest attribute or its default value if undefined.
     *
     * @param attr the attribute
     * @return the value of the attribute.
     * @see #getAttribute(Map.Entry)
     */
    protected <T> T attribute(Entry<String, T> attr) {
        return sup != null ? sup.attribute(attr) : attribute0(attr);
    }

    @SuppressWarnings("unchecked")
    private <T> T attribute00(Entry<String, T> attr) {
        final Object[] conf = ATTRIBS.get(name(attr));
//        if (conf == null)
//            throw new IllegalArgumentException("Attribute " + attr.getKey() + " has not been registered with ATTRIBUTE");
        final T type = type(attr);
        T value = oc.getAttribute0(name(attr), type);
        if (isEmpty(value))
            value = defaultValue(type, (T) (conf != null ? conf[ATTRIB_DEFAULT] : null));
        setContext("attribute", attr.getKey(), value);
        return value;
    }

    private <T> T parseAttribute(String attr, T type, String s) {
        try {
            return parse(expand(s), type, this);
        } catch (RuntimeException e) {
            throw new IllegalArgumentException("Error parsing attribute " + attr + ". Expected " + typeString(type) + " but was: " + s, e);
        }
    }

    private <T> T getAttribute0(String attr, T type) {
        T value = null;
        final String majorJavaVersion = majorJavaVersion(oc.javaVersion);
        if (manifest != null) {
            value = merge(value, parseAttribute(attr, type, getAttributes(manifest, null, null).getValue(attr)));
            if (majorJavaVersion != null)
                value = merge(value, parseAttribute(attr, type, getAttributes(manifest, null, "java-" + majorJavaVersion).getValue(attr)));
            value = merge(value, parseAttribute(attr, type, getPlatformAttribute(null, attr)));
            if (getMode() != null && allowsModal(attr)) {
                value = merge(value, parseAttribute(attr, type, getAttributes(manifest, mode, null).getValue(attr)));
                if (majorJavaVersion != null)
                    value = merge(value, parseAttribute(attr, type, getAttributes(manifest, mode, "java-" + majorJavaVersion).getValue(attr)));
                value = merge(value, parseAttribute(attr, type, getPlatformAttribute(getMode(), attr)));
            }
            setContext("attribute of " + jarFile, attr, value);
        }
        return value;
    }

    private String getPlatformAttribute(String mode, String attr) {
        if (PLATFORM == null)
            return null;
        String value = null;
        if (value == null)
            value = getAttributes(manifest, mode, PLATFORM).getValue(attr);
        if (value == null && isUnix())
            value = getAttributes(manifest, mode, OS_UNIX).getValue(attr);
        if (value == null && (isUnix() || isMac()))
            value = getAttributes(manifest, mode, OS_POSIX).getValue(attr);
        return value;
    }

    private static Attributes getAttributes(Manifest manifest, String mode, String platform) {
        if (emptyToNull(mode) == null && emptyToNull(platform) == null)
            return manifest.getMainAttributes();
        if (emptyToNull(mode) == null)
            return getAttributes(manifest, platform);
        if (emptyToNull(platform) == null)
            return getAttributes(manifest, mode);
        return getAttributes(manifest, mode + "-" + platform);
    }

    /**
     * Tests whether the given attribute is found in the manifest.
     *
     * @param attr the attribute
     */
    protected final boolean hasAttribute(Entry<String, ?> attr) {
        return !isEmpty(getAttribute(attr));
    }

    private boolean allowsModal(String attr) {
        final Object[] vals = ATTRIBS.get(attr);
        return vals != null ? (Boolean) vals[ATTRIB_MODAL] : true;
    }

    //<editor-fold defaultstate="collapsed" desc="Attribute Types and Parsing">
    /////////// Attribute Types and Parsing ///////////////////////////////////
    /**
     * Represents the attribute type {@code String}
     */
    protected static final String T_STRING() {
        return "";
    }

    /**
     * Represents an attribute type that contains a file path, dependency or class name
     */
    protected static final Object T_FILE() {
        return T_FILE("");
    }

    /**
     * Represents an attribute type that contains a file path, dependency or class name
     */
    protected static final Object T_FILE(String type) {
        return new AtomicReference<Object>(type);
    }

    /**
     * Represents the attribute type {@code Boolean}
     */
    protected static final Boolean T_BOOL() {
        return false;
    }

    /**
     * Represents the attribute type {@code Long}
     */
    protected static final Long T_LONG() {
        return 0L;
    }

    /**
     * Represents the attribute type {@code Double}
     */
    protected static final Double T_DOUBLE() {
        return 0.0;
    }

    /**
     * A {@code List} of type {@code type}
     *
     * @param type One of {@link #T_STRING() T_STRING}, {@link #T_FILE() T_FILE}, {@link #T_BOOL() T_BOOL}, {@link #T_LONG() T_LONG}, {@link #T_DOUBLE() T_DOUBLE}
     */
    protected static final <E> List<E> T_LIST(E type) {
        return singletonList(type);
    }

    /**
     * A {@code Set} of type {@code type}
     *
     * @param type One of {@link #T_STRING() T_STRING}, {@link #T_FILE() T_FILE}, {@link #T_BOOL() T_BOOL}, {@link #T_LONG() T_LONG}, {@link #T_DOUBLE() T_DOUBLE}
     */
    protected static final <E> Set<E> T_SET(E type) {
        return singleton(type);
    }

    /**
     * A {@code Map} from type {@code keyType} to type {@code valType}
     *
     * @param keyType      One of {@link #T_STRING() T_STRING}, {@link #T_FILE() T_FILE}, {@link #T_BOOL() T_BOOL}, {@link #T_LONG() T_LONG}, {@link #T_DOUBLE() T_DOUBLE}
     * @param valType      One of {@link #T_STRING() T_STRING}, {@link #T_FILE() T_FILE}, {@link #T_BOOL() T_BOOL}, {@link #T_LONG() T_LONG}, {@link #T_DOUBLE() T_DOUBLE}
     * @param defaultValue The default value for a key without a value in the attribute string, or {@code null} if all keys must explicitly specify a value.
     */
    @SuppressWarnings("unchecked")
    protected static final <K, V> Map<K, V> T_MAP(K keyType, V valType, V defaultValue) {
        if (defaultValue != null) {
            final Map<K, V> map = new LinkedHashMap<>();
            map.put(keyType, valType);
            map.put(null, promote(defaultValue, valType));
            return map;
        } else
            return singletonMap(keyType, valType);
    }

    @SuppressWarnings("unchecked")
    private static boolean isValidType(Object type) {
        if (type == null)
            return false;
        Object etype = null;
        if (type instanceof Collection) {
            if (!(type instanceof List || type instanceof Set))
                return false;
            etype = ((Collection<?>) type).iterator().next();
        } else if (type instanceof Map) {
            final Map.Entry<String, ?> desc = ((Map<String, ?>) type).entrySet().iterator().next();
            etype = desc.getValue();
        } else if (type instanceof AtomicReference) {
            return ((AtomicReference<?>) type).get() instanceof String;
        }

        if (etype != null) {
            if (etype instanceof Collection || etype instanceof Map)
                return false;
            return isValidType(etype);
        } else
            return ((Collection<Class>) (Object) asList(String.class, Boolean.class, Long.class, Double.class)).contains(type.getClass());
    }

    private static String typeString(Object type) {
        if (type instanceof Collection) {
            final Object etype = ((Collection<?>) type).iterator().next();
            final String collType = type instanceof Set ? "Set" : "List";
            return collType + " of " + typeString(etype) + " in the form \"v1 v2 ...\"";
        } else if (type instanceof Map) {
            final Map.Entry<String, ?> desc = ((Map<String, ?>) type).entrySet().iterator().next();
            final Object ktype = desc.getKey();
            final Object vtype = desc.getValue();
            return "map of " + typeString(ktype) + " to " + typeString(vtype) + " in the form \"k1=v1 k2=v2 ...\"";
        } else
            return type instanceof AtomicReference ? "path or dependency" : type.getClass().getSimpleName();
    }

    @SuppressWarnings("unchecked")
    private <T> T defaultValue(T type, T d) {
        if (d == null) {
            if (type instanceof List)
                return (T) emptyList();
            if (type instanceof Set)
                return (T) emptySet();
            if (type instanceof Map)
                return (T) emptyMap();
        }
        return d;
    }

    // visible for testing
    @SuppressWarnings("unchecked")
    static <T> T parse(String s, T type, Capsule capsule) {
        if (s == null)
            return null;
        if (type instanceof Collection) {
            final Object etype = ((Collection<?>) type).iterator().next();
            final List<String> slist = parse(s);
//            if (type instanceof List && etype instanceof String)
//                return (T) slist;
            final Collection<Object> coll = type instanceof Set ? new LinkedHashSet<>() : new ArrayList<>();
            for (String se : slist)
                coll.add(parse(se, etype, capsule));
            return (T) coll;
        } else if (type instanceof Map) {
            final Iterator<Map.Entry<?, ?>> it = ((Map) type).entrySet().iterator();
            final Map.Entry<?, ?> desc = it.next();
            final Object ktype = desc.getKey();
            final Object vtype = desc.getValue();
            final Object defaultValue = it.hasNext() ? it.next().getValue() : null;
            final String sdefaultValue = defaultValue != null ? defaultValue.toString() : null;

            final Map<String, String> smap = parse(s, sdefaultValue);
//            if (ktype instanceof String && vtype instanceof String)
//                return (T) smap;
            final Map<Object, Object> map = new LinkedHashMap<>();
            for (Map.Entry<String, String> se : smap.entrySet())
                map.put(parsePrimitive(se.getKey(), ktype, capsule), parsePrimitive(se.getValue(), vtype, capsule));
            return (T) map;
        } else
            return parsePrimitive(s, type, capsule);
    }

    @SuppressWarnings("unchecked")
    private static <T> T parsePrimitive(String s, T type, Capsule capsule) {
        if (s == null)
            return null;
        if (type instanceof AtomicReference)
            return (T) capsule.sanitize(s);
        if (type instanceof String)
            return (T) s;
        if (type instanceof Boolean)
            return (T) (Boolean) Boolean.parseBoolean(s);
        if (type instanceof Long)
            return (T) (Long) Long.parseLong(s);
        if (type instanceof Double)
            return (T) (Double) Double.parseDouble(s);
        throw new IllegalArgumentException("Unsupported primitive attribute type: " + type.getClass().getName());
    }

    @SuppressWarnings("unchecked")
    private static <T> T promote(Object x, T type) {
        if (!(x instanceof Number && type instanceof Number))
            return (T) x;

        if (x instanceof Integer) {
            if (type instanceof Long)
                x = Long.valueOf((Integer) x);
            else if (type instanceof Double)
                x = Double.valueOf((Integer) x);
        }
        return (T) x;
    }

    private static List<String> parse(String value) {
        return split(value, "\\s+");
    }

    private static Map<String, String> parse(String value, String defaultValue) {
        return split(value, '=', "\\s+", defaultValue);
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="T_FILE handling">
    /////////// T_FILE handling ///////////////////////////////////
    private static boolean hasFILE_T(Object type) {
        if (type instanceof Collection) {
            final Object etype = ((Collection<?>) type).iterator().next();
            return hasFILE_T(etype);
        } else if (type instanceof Map) {
            final Map.Entry<String, ?> desc = ((Map<String, ?>) type).entrySet().iterator().next();
            final Object ktype = desc.getKey();
            final Object vtype = desc.getValue();
            return hasFILE_T(ktype) || hasFILE_T(vtype);
        } else
            return type instanceof AtomicReference;
    }

    private <T> T lookupInAttribute(T value, Entry<String, T> attrib) {
        return lookupInAttribute(value, type(attrib), attrib, value);
    }

    @SuppressWarnings("unchecked")
    private <T, T1> T lookupInAttribute(Object o, T type, Entry<String, T1> attrib, T1 value) {
        if (o == null)
            return null;
        if (type instanceof Collection) {
            final Object etype = ((Collection<?>) type).iterator().next();
            final Collection<?> coll0 = (Collection<?>) o;
            final Collection<Object> coll = type instanceof Set ? new LinkedHashSet<>() : new ArrayList<>();
            for (Object e : coll0)
                coll.add(e instanceof String ? lookupInAttribute(e, etype, attrib, value) : e);
            return (T) coll;
        } else if (type instanceof Map) {
            final Iterator<Map.Entry<?, ?>> it = ((Map) type).entrySet().iterator();
            final Map.Entry<?, ?> desc = it.next();
            final Object ktype = desc.getKey();
            final Object vtype = desc.getValue();
            final Map<?, ?> map0 = (Map<?, ?>) o;
            final Map<Object, Object> map = new HashMap<>();
            for (Map.Entry<?, ?> e : map0.entrySet())
                map.put(lookupInAttribute(e.getKey(), ktype, attrib, value), lookupInAttribute(e.getValue(), vtype, attrib, value));
            return (T) map;
        } else if (type instanceof AtomicReference) {
            return (T) (o instanceof String ? lookup((String) o, ((AtomicReference<String>) type).get(), attrib, (value instanceof Map
                    ? ((Map<Object, Object>) value).get(o) : null)) : o);
        } else
            return (T) o;
    }
    //</editor-fold>

    private static final Attributes EMPTY_ATTRIBUTES = new Attributes();

    private static Attributes getAttributes(Manifest manifest, String name) {
//        Attributes as =  = manifest.getAttributes(name);
//        return as != null ? as : EMPTY_ATTRIBUTES;
        for (Map.Entry<String, Attributes> entry : manifest.getEntries().entrySet()) {
            if (entry.getKey().equalsIgnoreCase(name))
                return entry.getValue();
        }
        return EMPTY_ATTRIBUTES;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Dependency Utils">
    /////////// Dependency Utils ///////////////////////////////////
    private static boolean isDependency(String lib) {
        return lib.contains(":") && !lib.contains(":\\");
    }

    private static final Pattern PAT_DEPENDENCY = Pattern.compile("(?<groupId>[^:\\(]+):(?<artifactId>[^:\\(]+)(:(?<version>\\(?[^:\\(]*))?(:(?<classifier>[^:\\(]+))?(\\((?<exclusions>[^\\(\\)]*)\\))?");

    private Path dependencyToLocalJar(Path jar, String dep, String type, Entry<String, ?> attrContext) {
        String res = dependencyToLocalJar0(jar, dep, type, attrContext);
        return res != null ? path(toNativePath(res)) : null;
    }

    private static String dependencyToLocalJar0(Path jar, String dep, String type, Entry<String, ?> attrContext) {
        final Matcher m = PAT_DEPENDENCY.matcher(dep);
        if (!m.matches())
            throw new IllegalArgumentException("Could not parse dependency: " + dep);
        final String group = emptyToNull(m.group("groupId"));
        final String artifact = emptyToNull(m.group("artifactId"));
        final String version = emptyToNull(m.group("version"));
        final String classifier = emptyToNull(m.group("classifier"));

        final boolean caplet = ATTR_CAPLETS.equals(attrContext);
        final String libdir = (caplet ? "capsule" : "lib");

        final String filename = artifact
                                + (version != null ? '-' + version : "")
                                + (classifier != null ? '-' + classifier : "")
                                + "." + type;

        final List<String> names = new ArrayList<>();
        if (group != null) {
            names.add(libdir + '/' + group + '/' + filename);
            names.add(libdir + '/' + group + '-' + filename);
        }
        names.add(libdir + '/' + filename);
        if (group != null) {
            names.add(group + "/" + filename);
            names.add(group + '-' + filename);
        }
        names.add(filename);

        Collections.reverse(names);
        int index = -1;
        try {
            for (String entry : cachedEntries(jar))
                index = Math.max(index, names.indexOf(entry));
        } catch (IOException e) {
            throw rethrow(e);
        }

        return index >= 0 ? names.get(index) : null;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Paths">
    /////////// Paths ///////////////////////////////////
    /**
     * Converts a string file/dependency descriptor listed in the manifest to an opaque file descriptor used in attributes of type {@link #T_FILE() T_FILE}).
     *
     * @param x           the file/dependency descriptor
     * @param type        the file type (extension), needed only for artifact coordinates; if {@code null}, the default ({@code jar}) is used.
     * @param attrContext the attribute containing the file reference to look up; may be {@code null}
     * @param context     if the attribute {@code attrContext} is a map, the value associated with {@code x}'s respective key; otherwise, {@code null}.
     * @return an opaque file descriptor that will later be resolved
     */
    protected final Object lookup(String x, String type, Entry<String, ?> attrContext, Object context) {
        Object res = cc.lookup0(x, nullToEmpty(type), attrContext, context);

        log(LOG_DEBUG, "lookup " + x + "(" + type + ", " + name(attrContext) + ") -> " + res);
        if (res == null)
            throw new RuntimeException("Lookup for " + x + " has failed.");
        return res;
    }

    /**
     * Same as {@link #lookup(String, String, Entry, Object) lookup(x, null, null, null)}
     */
    protected final Object lookup(String x) {
        return lookup(x, null, null, null);
    }

    /**
     * Same as {@link #lookup(String, String, Entry, Object) lookup(x, null, attrContext, null)}
     */
    protected final Object lookup(String x, Entry<String, ?> attrContext) {
        return lookup(x, null, attrContext, null);
    }

    /**
     * For internal use; subject to change/removal.
     *
     * @deprecated exclude from javadocs
     */
    protected Object lookup0(Object x, String type, Entry<String, ?> attrContext, Object context) {
        _ct = unsafe(getCallTarget(Capsule.class));
        final String target = (_ct != null ? _ct.getClass().getName() : Capsule.class.getName()) + '@' + Integer.toHexString(System.identityHashCode(_ct));
        log(LOG_DEBUG, "lookup0 " + target + " " + x);
        final Object res = _ct != null ? _ct.lookup0(x, type, attrContext, context) : lookup00(x, type, attrContext, context);
        log(LOG_DEBUG, "lookup0 " + target + " " + x + " -> " + res);
        return res;
    }

    private Object lookup00(Object x, String type, Entry<String, ?> attrContext, Object context) {
        if (x instanceof String) {
            String desc = (String) x;

            final boolean isDependency = isDependency(desc);
            if (!isDependency) {
                if (!desc.contains(".") && !type.isEmpty())
                    desc += "." + type;
                desc = toNativePath(desc);
            }

            if (isDependency)
                x = dependencyToLocalJar(getJarFile(), desc, type.isEmpty() ? "jar" : type, attrContext);
            else if (isGlob(desc))
                x = listJar(getJarFile(), desc, false);
            else
                x = path(desc);
        }
        if (x == null)
            return null;

        if (ATTR_NATIVE_DEPENDENCIES.equals(attrContext)) {
            if (type != null && !"jar".equals(type)) {
                if (x instanceof Entry)
                    x = ((Entry<?, ?>) x).getValue();
                x = new Object[]{x, context};
            }
        }

        if (asList(ATTR_APP_ARTIFACT, ATTR_SCRIPT, ATTR_NATIVE_DEPENDENCIES).contains(attrContext)) {
            if (!(x instanceof Entry))
                x = mutableEntry(attrContext, x);
        }

        return x;
    }

    /**
     * Resolves a file descriptor returned from {@code lookup}.
     * This method may have side effects, such as writing to the file system (but they should be idempotent).
     * It is not allowed to access the paths returned from this method on the file system.
     *
     * @param x the value returned from {@code lookup}
     * @return the resolved paths
     */
    protected final List<Path> resolve(Object x) {
        final List<Path> res = cc.resolve0(x);
        log(LOG_DEBUG, "resolve " + x + " -> " + res);
        if (res == null)
            throw new RuntimeException("Could not resolve " + x);
        if (res.isEmpty())
            log(LOG_VERBOSE, "WARNING resolve " + x + " was empty");
        return res;
    }

    private List<Path> resolve(List<Object> ps) {
        if (ps == null)
            return null;
        final List<Path> res = new ArrayList<>(ps.size());
        for (Object p : ps)
            addAllIfAbsent(res, resolve(p));
        return res;
    }

    /**
     * For internal use; subject to change/removal.
     *
     * @deprecated exclude from javadocs
     */
    protected List<Path> resolve0(Object x) {
        _ct = unsafe(getCallTarget(Capsule.class));
        final String target = (_ct != null ? _ct.getClass().getName() : Capsule.class.getName()) + '@' + Integer.toHexString(System.identityHashCode(_ct));
        log(LOG_DEBUG, "resolve0 " + target + " " + x);
        final List<Path> res = _ct != null ? _ct.resolve0(x) : resolve00(x);
        log(LOG_DEBUG, "resolve0 " + target + " " + x + " -> " + res);
        return res;
    }

    /**
     * Returns the path or paths to the given file descriptor.
     * The given descriptor can be a dependency, a file name (relative to the app cache)
     * or a glob pattern (again, relative to the app cache). The returned list can contain more than one element
     * if a dependency is given and it resolves to more than a single artifact, or if a glob pattern is given,
     * which matches more than one file.
     */
    private List<Path> resolve00(Object x) {
        if (x == null)
            return null;

        if (x instanceof Collection) {
            final List<Path> res = new ArrayList<>();
            for (Object xe : ((Collection<?>) x))
                addAllIfAbsent(res, resolve(xe));
            return res;
        }

        if (x instanceof Entry) {
            final Entry<Entry<String, ?>, ?> context = (Entry<Entry<String, ?>, ?>) x;
            final Entry<String, ?> attr = context.getKey();
            x = context.getValue();

            if (x instanceof Collection) {
                final List<Path> res = new ArrayList<>();
                for (Object xe : ((Collection<?>) x))
                    addAllIfAbsent(res, resolve(mutableEntry(context, xe)));
                return res;
            }

            if (ATTR_APP_ARTIFACT.equals(attr)) {
                final List<Path> jars;
                if (x instanceof Path)
                    jars = Arrays.asList((Path) x);
                else if (x instanceof List && firstOrNull((List<?>) x) instanceof Path)
                    jars = (List<Path>) x;
                else
                    jars = resolve(x);

                final Path jar = simpleResolve(firstOrNull(jars));
                final Manifest man = getManifest(jar);
                oc.appArtifactMainClass = getMainClass(man);

                final List<Path> res = jars;
//                final List<Path> res = new ArrayList<>();
//                addAllIfAbsent(res, resolveJar(jar, man));
//                addAllIfAbsent(res, jars.subList(1, jars.size()));

                x = res;
            } else if (ATTR_SCRIPT.equals(attr)) {
                ensureExecutable(simpleResolve(x));
            } else if (ATTR_NATIVE_DEPENDENCIES.equals(attr)) {
                final Object[] fileAndRename = (Object[]) x;
                final Path lib = only(resolve(fileAndRename[0]));
                final String rename = (String) fileAndRename[1];
                Path res = lib;

                if (rename != null && !rename.isEmpty() && !lib.startsWith(getWritableAppCache())) {
                    try {
                        res = getWritableAppCache().resolve(rename);
                        log(LOG_DEBUG, "Copying native lib " + lib + " to " + res);
                        Files.copy(lib, res, StandardCopyOption.REPLACE_EXISTING);
                        fileAndRename[0] = res;
                    } catch (IOException e) {
                        throw new RuntimeException("Exception while copying native libs", e);
                    }
                }

                x = res;
            }
            return resolve(x);
        }

        if (x instanceof Path && ((Path) x).isAbsolute()) {
            Path p = ((Path) x).normalize();

            //
            final Path currentJavaHome = Paths.get(System.getProperty(PROP_JAVA_HOME));
            if (p.startsWith(Paths.get(System.getProperty(PROP_JAVA_HOME))))
                p = move(p, currentJavaHome, getJavaHome());

            return singletonList(p);
        } else {
            final Path p = simpleResolve(x);
            if (p != null)
                return resolve(p);
        }

        throw new RuntimeException("Could not resolve item " + x);
    }

    private Path simpleResolve(Object x) {
        if (x instanceof Path) {
            Path p = (Path) x;
            p = p.isAbsolute() ? p : appDir().resolve(p);
            p = p.toAbsolutePath().normalize();

            return p;
        }

        if (x instanceof URL) {
            final URL url = (URL) x;
            if ("jar".equals(url.getProtocol())) {
                if (!path(getBefore(url.getPath(), '!')).toAbsolutePath().equals(getJarFile()))
                    throw new AssertionError("URL " + url + " not pointing at capsule JAR " + getJarFile());
                return simpleResolve(path(getAfter(url.getPath(), '!').substring(1)));
            }
        }

        return null;
    }

    private List<Path> resolveJar(Path jar, Manifest man) {
        if (man == null)
            man = getManifest(jar);

        final List<Path> res = new ArrayList<>();
        res.add(jar);
        jar = simpleResolve(jar);

        // add JAR's manifest's Class-Path
        for (String e : nullToEmpty(parse(man.getMainAttributes().getValue(ATTR_CLASS_PATH)))) {
            Path p;
            try {
                p = path(new URL(e).toURI());
            } catch (MalformedURLException | URISyntaxException ex) {
                p = jar.getParent().resolve(path(toNativePath(e)));
            }
            if (!res.contains(p))
                res.add(toAbsolutePath(p));
        }
        return res;
    }

    private String processOutgoingPath(Object p) {
        return toString(firstOrNull(resolve(p)));
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="JAR Extraction">
    /////////// JAR Extraction ///////////////////////////////////
    private static void extractJar(JarInputStream jar, Path targetDir) throws IOException {
        for (JarEntry entry; (entry = jar.getNextJarEntry()) != null;) {
            if (entry.isDirectory() || !shouldExtractFile(entry.getName()))
                continue;

            if (Files.exists(targetDir.resolve(entry.getName()))) {
                log(LOG_QUIET, "Warning: duplicate file " + entry.getName() + " in capsule");
                continue;
            }

            writeFile(targetDir, entry.getName(), jar);
        }
    }

    private static boolean shouldExtractFile(String fileName) {
        if (fileName.equals(Capsule.class.getName().replace('.', '/') + ".class")
            || (fileName.startsWith(Capsule.class.getName().replace('.', '/') + "$") && fileName.endsWith(".class")))
            return false;
        if (fileName.endsWith(".class"))
            return false;
        if (fileName.startsWith("capsule/") && !fileName.endsWith(".jar"))
            return false;
        if (fileName.startsWith("META-INF/"))
            return false;
        return true;
    }

    private List<Path> listJar(Path jar, String glob, boolean regular) {
        final long start = clock();
        final List<Path> res = new ArrayList<>();
        final Pattern p = Pattern.compile(globToRegex(glob));
        try (ZipInputStream zis = openJarInputStream(jar)) {
            for (ZipEntry entry; (entry = zis.getNextEntry()) != null;) {
                if ((!regular || !entry.isDirectory()) && p.matcher(entry.getName()).matches())
                    res.add(path(entry.getName())); // new URL("jar", "", jar + "!/" + entry.getName())
            }
        } catch (IOException e) {
            throw rethrow(e);
        }
        time("listJar", start);
        return res;
    }

    private Path mergeCapsule(Path wrapperCapsule, Path wrappedCapsule, Path outCapsule) throws IOException {
        try {
            if (Objects.equals(wrapperCapsule, wrappedCapsule)) {
                Files.copy(wrappedCapsule, outCapsule);
                return outCapsule;
            }

            final String wrapperVersion = VERSION;
            final String wrappedVersion;
            try {
                wrappedVersion = getCapsuleVersion(newClassLoader(null, wrapperCapsule).loadClass(Capsule.class.getName()));
            } catch (ClassNotFoundException e) {
                throw new RuntimeException(wrapperCapsule + " is not a valid capsule");
            }
            if (wrappedVersion == null)
                throw new RuntimeException(wrapperCapsule + " is not a valid capsule");
            if (Integer.parseInt(getBefore(wrapperVersion, '.')) != Integer.parseInt(getBefore(wrappedVersion, '.')))
                throw new RuntimeException("Incompatible Capsule versions: " + wrapperCapsule + " (" + wrapperVersion + "), " + wrappedCapsule + " (" + wrappedVersion + ")");
            final int higherVersion = compareVersions(wrapperVersion, wrappedVersion);

            try (final OutputStream os = Files.newOutputStream(outCapsule);
                 final JarInputStream wr = openJarInputStream(wrapperCapsule);
                 final JarInputStream wd = copyJarPrefix(Files.newInputStream(wrappedCapsule), os)) {

                final JarInputStream first = higherVersion >= 0 ? wr : wd;
                final JarInputStream second = higherVersion < 0 ? wr : wd;

                final Manifest man = new Manifest(wd.getManifest());

                final String wrMainClass = wr.getManifest().getMainAttributes().getValue(ATTR_MAIN_CLASS);
                if (!Capsule.class.getName().equals(wrMainClass)) {
                    if (first != wr)
                        throw new RuntimeException("Main class of wrapper capsule " + wrapperCapsule + " (" + wrMainClass + ") is not " + Capsule.class.getName()
                                                   + " and is of lower version ( " + wrapperVersion + ") than that of the wrapped capsule " + wrappedCapsule + " (" + wrappedVersion + "). Cannot merge.");
                    man.getMainAttributes().putValue(ATTR_MAIN_CLASS, wrMainClass);
                }

                final List<String> wrCaplets = nullToEmpty(parse(wr.getManifest().getMainAttributes().getValue(name(ATTR_CAPLETS))));
                final ArrayList<String> caplets = new ArrayList<>(nullToEmpty(parse(man.getMainAttributes().getValue(name(ATTR_CAPLETS)))));
                addAllIfAbsent(caplets, wrCaplets);

                man.getMainAttributes().putValue(name(ATTR_CAPLETS), join(caplets, " "));

                try (final JarOutputStream out = new JarOutputStream(os, man)) {
                    final Set<String> copied = new HashSet<>();
                    for (JarEntry entry; (entry = first.getNextJarEntry()) != null;) {
                        if (!entry.getName().equals(MANIFEST_NAME)) {
                            out.putNextEntry(new JarEntry(entry));
                            copy(first, out);
                            out.closeEntry();
                            copied.add(entry.getName());
                        }
                    }
                    for (JarEntry entry; (entry = second.getNextJarEntry()) != null;) {
                        if (!entry.getName().equals(MANIFEST_NAME) && !copied.contains(entry.getName())) {
                            out.putNextEntry(new JarEntry(entry));
                            copy(second, out);
                            out.closeEntry();
                        }
                    }

                    log(LOG_VERBOSE, "Testing capsule " + outCapsule);
                    newCapsule0(newClassLoader(ClassLoader.getSystemClassLoader(), outCapsule), outCapsule); // test capsule
                    log(LOG_VERBOSE, "Done testing capsule " + outCapsule);

                    return outCapsule;
                }
            }
        } catch (Exception e) {
            try {
                Files.delete(outCapsule);
            } catch (IOException ex) {
            }
            throw e;
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Path Utils">
    /////////// Path Utils ///////////////////////////////////
    private FileSystem getFileSystem() {
        return cc.jarFile != null ? cc.jarFile.getFileSystem() : FileSystems.getDefault();
    }

    private Path path(String p, String... more) {
        return getFileSystem().getPath(p, more);
    }

    private Path path(URI uri) {
        return getFileSystem().provider().getPath(uri);
    }

    private List<Path> toPath(List<String> ps) {
        if (ps == null)
            return null;
        final List<Path> aps = new ArrayList<>(ps.size());
        for (String p : ps)
            aps.add(path(p));
        return aps;
    }

    private static Path toAbsolutePath(Path p) {
        return p != null ? p.toAbsolutePath().normalize() : null;
    }

    private static List<Path> resolve(Path root, List<String> ps) {
        if (ps == null)
            return null;
        final List<Path> aps = new ArrayList<>(ps.size());
        for (String p : ps)
            aps.add(root.resolve(p));
        return aps;
    }

    private Path sanitize(Path p) {
        if (p == null)
            return null;
        final Path path = p.normalize();
        if (p.isAbsolute()) {
            if (getAppDir() != null && path.startsWith(getAppDir()))
                return path;
            if (path.startsWith(getJavaHome()) || path.startsWith(Paths.get(System.getProperty(PROP_JAVA_HOME))))
                return path;
        } else if (!path.startsWith(".."))
            return path;

        throw new IllegalArgumentException("Path " + p + " is not local to app cache " + getAppDir());
    }

    private String sanitize(String p) {
        if (isDependency(p))
            return p;
        if (p.contains("/") || p.contains(FILE_SEPARATOR)) {
            p = toNativePath(p);
            sanitize(Paths.get(p));
        }
        return p;
    }

    private static Path toFriendlyPath(Path p) {
        if (p.isAbsolute()) {
            Path rel = p.getFileSystem().getPath("").toAbsolutePath().relativize(p);
            if (rel.normalize().equals(rel))
                return rel;
        }
        return p;
    }

    /**
     * Returns a path to a file or directory moved from {@code fromDir} to {@code toDir}.
     * This method does not actually moves any files in the filesystem.
     *
     * @param what    the path to move; must start with {@code fromDir}
     * @param fromDir the directory containing {@code what}
     * @param toDir   the directory {@code what} is moved to
     * @return the moved path, which will start with {@code toDir}.
     */
    protected static Path move(Path what, Path fromDir, Path toDir) {
        if (!what.startsWith(fromDir))
            throw new IllegalArgumentException(what + " is not under " + fromDir);
        return toDir.resolve(fromDir.relativize(what));
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="OS">
    /////////// OS ///////////////////////////////////
    /**
     * Tests whether the current OS is Windows.
     */
    @SuppressWarnings("StringEquality")
    protected static final boolean isWindows() {
        return PLATFORM == OS_WINDOWS;
    }

    /**
     * Tests whether the current OS is MacOS.
     */
    @SuppressWarnings("StringEquality")
    protected static final boolean isMac() {
        return PLATFORM == OS_MACOS;
    }

    /**
     * Tests whether the current OS is UNIX/Linux.
     */
    @SuppressWarnings("StringEquality")
    protected static final boolean isUnix() {
        return PLATFORM == OS_LINUX || PLATFORM == OS_SOLARIS || PLATFORM == OS_BSD
               || PLATFORM == OS_AIX || PLATFORM == OS_HP_UX;
    }

    private static String getOS() {
        if (OS.startsWith("windows"))
            return OS_WINDOWS;
        if (OS.startsWith("mac"))
            return OS_MACOS;
        if (OS.contains("linux"))
            return OS_LINUX;
        if (OS.contains("solaris") || OS.contains("sunos") || OS.contains("illumos"))
            return OS_SOLARIS;
        if (OS.contains("bsd"))
            return OS_BSD;
        if (OS.contains("aix"))
            return OS_AIX;
        if (OS.contains("hp-ux"))
            return OS_HP_UX;
        if (OS.contains("vms"))
            return OS_VMS;

        log(LOG_QUIET, "WARNING Unrecognized OS: " + System.getProperty(PROP_OS_NAME));
        return null;
    }

    /**
     * The suffix of a native library on this OS.
     */
    protected static final String getNativeLibExtension() {
        if (isWindows())
            return "dll";
        if (isMac())
            return "dylib";
        if (isUnix())
            return "so";
        throw new RuntimeException("Unsupported operating system: " + System.getProperty(PROP_OS_NAME));
    }

    private static long getMaxCommandLineLength() {
        if (isWindows())
            return WINDOWS_MAX_CMD;
        return Long.MAX_VALUE;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="JAR Utils">
    /////////// JAR Utils ///////////////////////////////////
    private static JarInputStream openJarInputStream(Path jar) throws IOException {
        return new JarInputStream(skipToZipStart(Files.newInputStream(jar), null));
    }

    private static JarInputStream copyJarPrefix(InputStream is, OutputStream os) throws IOException {
        return new JarInputStream(skipToZipStart(is, null));
    }

    protected static InputStream getEntryInputStream(Path jar, String name) throws IOException {
        return getEntry(openJarInputStream(jar), name);
    }

    private static InputStream getEntry(ZipInputStream zis, String name) throws IOException {
        for (ZipEntry entry; (entry = zis.getNextEntry()) != null;) {
            if (entry.getName().equals(name))
                return zis;
        }
        return null;
    }

    private static String getMainClass(Path jar) {
        return getMainClass(getManifest(jar));
    }

    private static String getMainClass(Manifest manifest) {
        if (manifest == null)
            return null;
        return manifest.getMainAttributes().getValue(ATTR_MAIN_CLASS);
    }

    private static Manifest getManifest(Path jar) {
        try (JarInputStream jis = openJarInputStream(jar)) {
            return jis.getManifest();
        } catch (IOException e) {
            throw new RuntimeException("Error reading manifest from " + jar, e);
        }
    }

    private static Map<Path, List<String>> jarEntriesCache = new HashMap<>();

    private static Iterable<String> cachedEntries(Path jar) throws IOException {
        final Map<Path, List<String>> cache = jarEntriesCache;
        if (cache != null && cache.containsKey(jar))
            return cache.get(jar);
        final List<String> entries = new ArrayList<>();
        try (ZipInputStream zis = openJarInputStream(jar)) {
            for (ZipEntry entry; (entry = zis.getNextEntry()) != null;)
                entries.add(entry.getName());
        }
        if (cache != null)
            cache.put(jar, entries);
        return entries;
    }

    private static final int[] ZIP_HEADER = new int[]{'P', 'K', 0x03, 0x04};

    private static InputStream skipToZipStart(InputStream is, OutputStream os) throws IOException {
        if (!is.markSupported())
            is = new BufferedInputStream(is);
        int state = 0;
        for (;;) {
            if (state == 0)
                is.mark(ZIP_HEADER.length);
            final int b = is.read();
            if (b < 0)
                throw new IllegalArgumentException("Not a JAR/ZIP file");
            if (state >= 0 && b == ZIP_HEADER[state]) {
                state++;
                if (state == ZIP_HEADER.length)
                    break;
            } else {
                state = -1;
                if (b == '\n' || b == 0) // start matching on \n and \0
                    state = 0;
            }
            if (os != null)
                os.write(b);
        }
        is.reset();
        return is;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="File Utils">
    /////////// File Utils ///////////////////////////////////
    private static void writeFile(Path targetDir, String fileName, InputStream is) throws IOException {
        fileName = toNativePath(fileName);
        final String dir = getDirectory(fileName);
        if (dir != null)
            Files.createDirectories(targetDir.resolve(dir));

        final Path targetFile = targetDir.resolve(fileName);
        Files.copy(is, targetFile);
    }

    private static String toNativePath(String filename) {
        if (filename.contains("://")) // detect URL
            return filename;
        final char ps = (!filename.contains("/") && filename.contains("\\")) ? '\\' : '/';
        return ps != FILE_SEPARATOR_CHAR ? filename.replace(ps, FILE_SEPARATOR_CHAR) : filename;
    }

    private static String getDirectory(String filename) {
        final int index = filename.lastIndexOf(FILE_SEPARATOR_CHAR);
        if (index < 0)
            return null;
        return filename.substring(0, index);
    }

    /**
     * Deletes the given file or directory (even if nonempty).
     */
    static void delete(Path path) throws IOException {
        log(LOG_DEBUG, "Deleting " + path);
        if (!Files.exists(path))
            return;
        if (Files.isDirectory(path)) {
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(path)) {
                for (Path f : ds)
                    delete(f);
            }
        }
        Files.delete(path);
    }

    /**
     * Copies the source file or directory (recursively) to the target location.
     */
    static void copy(Path source, Path target) throws IOException {
        Files.copy(source, target, StandardCopyOption.COPY_ATTRIBUTES, StandardCopyOption.REPLACE_EXISTING);
        if (Files.isDirectory(source)) {
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(source)) {
                for (Path f : ds)
                    copy(f, target.resolve(f.getFileName()));
            }
        }
    }

    private static Path ensureExecutable(Path file) {
        if (!Files.isExecutable(file)) {
            try {
                Set<PosixFilePermission> perms = Files.getPosixFilePermissions(file);
                if (!perms.contains(PosixFilePermission.OWNER_EXECUTE)) {
                    Set<PosixFilePermission> newPerms = EnumSet.copyOf(perms);
                    newPerms.add(PosixFilePermission.OWNER_EXECUTE);
                    Files.setPosixFilePermissions(file, newPerms);
                }
            } catch (UnsupportedOperationException e) {
            } catch (IOException e) {
                throw rethrow(e);
            }
        }
        return file;
    }

    /**
     * Copies the input stream to the output stream.
     * Neither stream is closed when the method returns.
     */
    static void copy(InputStream is, OutputStream out) throws IOException {
        final byte[] buffer = new byte[1024];
        for (int bytesRead; (bytesRead = is.read(buffer)) != -1;)
            out.write(buffer, 0, bytesRead);
        out.flush();
    }

    private static Path getTempDir() {
        try {
            return Paths.get(getProperty(PROP_TMP_DIR));
        } catch (Exception e) {
            return null;
        }
    }

    private static Path getExistingAncestor(Path p) {
        p = p.toAbsolutePath().getParent();
        while (p != null && !Files.exists(p))
            p = p.getParent();
        return p;
    }

    /**
     * Returns the permissions of the given file or directory.
     */
    protected static FileAttribute<?>[] getPermissions(Path p) throws IOException {
        final List<FileAttribute> attrs = new ArrayList<>();

        final PosixFileAttributeView posix = Files.getFileAttributeView(p, PosixFileAttributeView.class);
        if (posix != null)
            attrs.add(PosixFilePermissions.asFileAttribute(posix.readAttributes().permissions()));

        return attrs.toArray(new FileAttribute[attrs.size()]);
    }

    private static boolean isGlob(String s) {
        return s.contains("*") || s.contains("?") || s.contains("{") || s.contains("[");
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="JRE Installations">
    /////////// JRE Installations ///////////////////////////////////
    private static boolean isJDK(Path javaHome) {
        final String name = javaHome.toString().toLowerCase();
        return !name.contains("jre") && (name.contains("jdk") || Files.exists(javaHome.resolve("include").resolve("jni.h")));
    }

    /**
     * Returns all found Java installations.
     *
     * @return a map from installations' versions to their respective (possibly multiple) paths
     */
    protected static Map<String, List<Path>> getJavaHomes() {
        if (JAVA_HOMES == null) {
            try {
                Path homesDir = null;
                for (Path d = Paths.get(getProperty(PROP_JAVA_HOME)); d != null; d = d.getParent()) {
                    if (d.getFileName() != null && isJavaDir(d.getFileName().toString()) != null) {
                        homesDir = d.getParent();
                        break;
                    }
                }
                Map<String, List<Path>> homes = getJavaHomes(homesDir);
                if (homes != null && isWindows())
                    homes = windowsJavaHomesHeuristics(homesDir, homes);
                JAVA_HOMES = homes;
            } catch (IOException e) {
                throw rethrow(e);
            }
        }
        return JAVA_HOMES;
    }

    private static Map<String, List<Path>> windowsJavaHomesHeuristics(Path dir, Map<String, List<Path>> homes) throws IOException {
        Path dir2 = null;
        if (dir.startsWith(WINDOWS_PROGRAM_FILES_1))
            dir2 = WINDOWS_PROGRAM_FILES_2.resolve(WINDOWS_PROGRAM_FILES_1.relativize(dir));
        else if (dir.startsWith(WINDOWS_PROGRAM_FILES_2))
            dir2 = WINDOWS_PROGRAM_FILES_1.resolve(WINDOWS_PROGRAM_FILES_2.relativize(dir));
        if (dir2 != null) {
            Map<String, List<Path>> allHomes = new HashMap<>(nullToEmpty(homes));
            multiputAll(allHomes, nullToEmpty(getJavaHomes(dir2)));
            return allHomes;
        } else
            return homes;
    }

    private static Map<String, List<Path>> getJavaHomes(Path dir) throws IOException {
        if (dir == null || !Files.isDirectory(dir))
            return null;
        final Map<String, List<Path>> dirs = new HashMap<>();
        try (DirectoryStream<Path> fs = Files.newDirectoryStream(dir)) {
            for (Path f : fs) {
                String ver;
                List<Path> homes;
                if (Files.isDirectory(f) && (ver = isJavaDir(f.getFileName().toString())) != null
                    && (homes = searchJavaHomeInDir(f)) != null && homes.size() > 0) {
                    if (parseJavaVersion(ver)[3] == 0)
                        ver = getActualJavaVersion(first(homes));
                    multiput(dirs, ver, homes);
                }
            }
        }
        return dirs;
    }

    private static String getJavaVersion(Path home) {
        if (home == null)
            return null;
        String ver;
        for (Path f = home; f != null && f.getNameCount() > 0; f = f.getParent()) {
            ver = isJavaDir(f.getFileName().toString());
            if (ver != null)
                return ver;
        }
        return getActualJavaVersion(home);
    }

    // visible for testing
    static String isJavaDir(String fileName) {
        /*
         * This method considers some well-known Java home directory naming schemes.
         * It will likely require changes to accomodate other schemes used by various package managers.
         */
        fileName = fileName.toLowerCase();
        if ((fileName.startsWith("java-") || fileName.startsWith("jdk-") || fileName.startsWith("jre-"))
            && (fileName.contains("-openjdk") || fileName.contains("-oracle"))) {
            final Matcher m = Pattern.compile("^[^\\-]+-([0-9\\.]+)-").matcher(fileName);
            if (!m.find())
                throw new RuntimeException("Cannot parse Java directory name: " + fileName);
            return shortJavaVersion(m.group(1));
        } else if (fileName.startsWith("jdk-") && (fileName.contains("-openjdk") || fileName.contains("-oracle"))) {
            final Matcher m = Pattern.compile("java-([0-9]+)-").matcher(fileName);
            m.find();
            return shortJavaVersion(m.group(1));
        } else if (fileName.startsWith("jdk") || fileName.startsWith("jre") || fileName.endsWith(".jdk") || fileName.endsWith(".jre")) {
            if (fileName.startsWith("jdk-") || fileName.startsWith("jre-"))
                fileName = fileName.substring(4);
            else if (fileName.startsWith("jdk") || fileName.startsWith("jre"))
                fileName = fileName.substring(3);

            if (fileName.endsWith(".jdk") || fileName.endsWith(".jre"))
                fileName = fileName.substring(0, fileName.length() - 4);
            return shortJavaVersion(fileName);
        } else
            return null;
    }

    private static List<Path> searchJavaHomeInDir(Path dir) throws IOException {
        final List<Path> homes = new ArrayList<>();
        final boolean jdk = isJDK(dir);
        if (isJavaHome(dir))
            homes.add(dir.toAbsolutePath());
        try (DirectoryStream<Path> fs = Files.newDirectoryStream(dir)) {
            for (Path f : fs) {
                if (Files.isDirectory(f)) {
                    if (isJavaHome(f))
                        homes.add(f.toAbsolutePath());
                    if (homes.size() >= 2 || (homes.size() >= 1 && !(jdk || isJDK(f))))
                        break;
                    final List<Path> rec = searchJavaHomeInDir(f);
                    if (rec != null)
                        homes.addAll(rec);
                }
            }
        }
        return homes;
    }

    private static boolean isJavaHome(Path dir) {
        return Files.isRegularFile(dir.resolve("bin").resolve("java" + (isWindows() ? ".exe" : "")));
    }

    private static Path getJavaExecutable0(Path javaHome) {
        final String exec = (isWindows() && System.console() == null) ? "javaw" : "java";
        return javaHome.resolve("bin").resolve(exec + (isWindows() ? ".exe" : ""));
    }

    private static final Pattern PAT_JAVA_VERSION_LINE = Pattern.compile(".*?\"(.+?)\"");

    private static String getActualJavaVersion(Path javaHome) {
        try {
            final String versionLine = first(exec(1, true, new ProcessBuilder(asList(getJavaExecutable0(javaHome).toString(), "-version"))));
            final Matcher m = PAT_JAVA_VERSION_LINE.matcher(versionLine);
            if (!m.matches())
                throw new IllegalArgumentException("Could not parse version line: " + versionLine);
            final String version = m.group(1);

            return version;
        } catch (Exception e) {
            throw rethrow(e);
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Version Strings">
    /////////// Version Strings ///////////////////////////////////
    // visible for testing
    static String shortJavaVersion(String v) {
        try {
            final String[] vs = v.split(SEPARATOR_DOT);
            if (vs.length == 1) {
                if (Integer.parseInt(vs[0]) < 5)
                    throw new RuntimeException("Unrecognized major Java version: " + v);
                v = "1." + v + ".0";
            }
            if (vs.length == 2)
                v += ".0";
            return v;
        } catch (NumberFormatException e) {
            return null;
        }
    }

    private static String majorJavaVersion(String v) {
        if (v == null)
            return null;
        final String[] vs = v.split(SEPARATOR_DOT);
        if (vs.length == 1)
            return vs[0];
        if (vs.length >= 2)
            return vs[1];
        throw new AssertionError("unreachable");
    }

    /**
     * Compares two dotted software versions, regarding only the first several version components.
     *
     * @param a first version
     * @param b second version
     * @param n the number of (most significant) components to consider
     * @return {@code 0} if {@code a == b}; {@code > 0} if {@code a > b}; {@code < 0} if {@code a < b};
     */
    protected static final int compareVersions(String a, String b, int n) {
        return compareVersions(parseJavaVersion(a), parseJavaVersion(b), n);
    }

    /**
     * Compares two dotted software versions.
     *
     * @param a first version
     * @param b second version
     * @return {@code 0} if {@code a == b}; {@code > 0} if {@code a > b}; {@code < 0} if {@code a < b};
     */
    protected static final int compareVersions(String a, String b) {
        return compareVersions(parseJavaVersion(a), parseJavaVersion(b));
    }

    private static int compareVersions(int[] a, int[] b) {
        return compareVersions(a, b, 5);
    }

    private static int compareVersions(int[] a, int[] b, int n) {
        for (int i = 0; i < n; i++) {
            if (a[i] != b[i])
                return a[i] - b[i];
        }
        return 0;
    }

    private static boolean equals(int[] a, int[] b, int n) {
        for (int i = 0; i < n; i++) {
            if (a[i] != b[i])
                return false;
        }
        return true;
    }

    private static final Pattern PAT_JAVA_VERSION = Pattern.compile("(?<major>\\d+)(\\.(?<minor>\\d+))?(?:\\.(?<patch>\\d+))?(_(?<update>\\d+))?(-(?<pre>[^-]+))?(-(?<build>.+))?");

    // visible for testing
    static int[] parseJavaVersion(String v) {
        final Matcher m = PAT_JAVA_VERSION.matcher(v);
        if (!m.matches())
            throw new IllegalArgumentException("Could not parse version: " + v);
        final int[] ver = new int[5];
        ver[0] = toInt(m.group("major"));
        ver[1] = toInt(m.group("minor"));
        ver[2] = toInt(m.group("patch"));
        ver[3] = toInt(m.group("update"));
        if (ver[0] > 1 && ver[1] == 0) {
            ver[1] = ver[0];
            ver[0] = 1;
        }
        final String pre = m.group("pre");
        if (pre != null) {
            if (pre.startsWith("rc"))
                ver[4] = -1;
            else if (pre.startsWith("beta"))
                ver[4] = -2;
            else if (pre.startsWith("ea"))
                ver[4] = -3;
        }
        return ver;
    }

    // visible for testing
    static String toJavaVersionString(int[] version) {
        final StringBuilder sb = new StringBuilder();
        sb.append(version[0]).append('.');
        sb.append(version[1]).append('.');
        sb.append(version[2]);
        if (version.length > 3 && version[3] > 0)
            sb.append('_').append(version[3]);
        if (version.length > 4 && version[4] != 0) {
            final String pre;
            switch (version[4]) {
                case -1:
                    pre = "rc";
                    break;
                case -2:
                    pre = "beta";
                    break;
                case -3:
                    pre = "ea";
                    break;
                default:
                    pre = "?";
            }
            sb.append('-').append(pre);
        }
        return sb.toString();
    }

    private static int toInt(String s) {
        return s != null ? Integer.parseInt(s) : 0;
    }

    private static int[] toInt(String[] ss) {
        int[] res = new int[ss.length];
        for (int i = 0; i < ss.length; i++)
            res[i] = ss[i] != null ? Integer.parseInt(ss[i]) : 0;
        return res;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="String Expansion">
    /////////// String Expansion ///////////////////////////////////
    private static final Pattern PAT_VAR = Pattern.compile("\\$(?:([a-zA-Z0-9_\\-]+)|(?:\\{([^\\}]*)\\}))");

    private String expand(String str) {
        if (str == null)
            return null;

        final StringBuffer sb = new StringBuffer();
        final Matcher m = PAT_VAR.matcher(str);
        while (m.find())
            m.appendReplacement(sb, Matcher.quoteReplacement(getVarValue(xor(m.group(1), m.group(2)))));
        m.appendTail(sb);
        str = sb.toString();

        // str = expandCommandLinePath(str);
        return str;
    }

    /**
     * Resolves {@code $VARNAME} or {@code ${VARNAME}} in attribute values.
     *
     * @param var the variable name
     * @return the variable's value
     */
    protected String getVarValue(String var) {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.getVarValue(var) : getVarValue0(var);
    }

    private String getVarValue0(String var) {
        String value = null;
        switch (var) {
            case VAR_CAPSULE_DIR:
                try {
                    value = processOutgoingPath(appDir());
                    break;
                } catch (IllegalStateException e) {
                    throw new IllegalStateException("Cannot resolve variable $" + var, e);
                }
            case VAR_CAPSULE_APP:
                if (getAppId() == null)
                    throw new RuntimeException("Cannot resolve variable $" + var + " in an empty capsule.");
                value = getAppId();
                break;

            case VAR_CAPSULE_JAR:
            case "0":
                value = processOutgoingPath(getJarFile());
                break;

            case VAR_JAVA_HOME:
                final String jhome = processOutgoingPath(getJavaHome());
                if (jhome == null)
                    throw new RuntimeException("Cannot resolve variable $" + var + "; Java home not set.");
                value = jhome;
                break;
        }
        if (value == null) {
            value = getProperty(var);
            if (value != null)
                log(LOG_DEBUG, "Resolved variable $" + var + " with a property");
        }
        if (value == null) {
            value = getenv(var);
            if (value != null)
                log(LOG_DEBUG, "Resolved variable $" + var + " with an environement variable");
        }
        if (value == null)
            throw new RuntimeException("Cannot resolve variable $" + var);
        return value;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="String Utils">
    /////////// String Utils ///////////////////////////////////
    private static String toString(Object o) {
        if (o == null)
            return null;
        if (o instanceof Path)
            return toString((Path) o);
        return o.toString();
    }

    private static String toString(Path p) {
        String s = p.toString();
        if (FILE_SEPARATOR_CHAR != '/' && isUnix())
            s = s.replace(FILE_SEPARATOR_CHAR, '/');
        return s;
    }

    private static List<String> split(String str, String separator) {
        if (str == null)
            return null;
        final String[] es = str.split(separator);
        final List<String> list = new ArrayList<>(es.length);
        for (String e : es) {
            e = e.trim();
            if (!e.isEmpty())
                list.add(e);
        }
        return list;
    }

    private static Map<String, String> split(String map, char kvSeparator, String separator, String defaultValue) {
        if (map == null)
            return null;
        Map<String, String> m = new LinkedHashMap<>();
        for (String entry : Capsule.split(map, separator)) {
            final String key = getBefore(entry, kvSeparator);
            String value = getAfter(entry, kvSeparator);
            if (value == null) {
                if (defaultValue != null)
                    value = defaultValue;
                else
                    throw new IllegalArgumentException("Element " + entry + " in \"" + map + "\" is not a key-value entry separated with " + kvSeparator + " and no default value provided");
            }
            m.put(key.trim(), value.trim());
        }
        return m;
    }

    private static String join(Collection<?> coll, String separator) {
        if (coll == null)
            return null;
        if (coll.isEmpty())
            return "";
        StringBuilder sb = new StringBuilder();
        for (Object e : coll) {
            if (e != null)
                sb.append(toString(e)).append(separator);
        }
        sb.delete(sb.length() - separator.length(), sb.length());
        return sb.toString();
    }

    private static String getBefore(String s, char separator) {
        final int i = s.indexOf(separator);
        if (i < 0)
            return s;
        return s.substring(0, i);
    }

    private static String getAfter(String s, char separator) {
        final int i = s.indexOf(separator);
        if (i < 0)
            return null;
        return s.substring(i + 1);
    }

    private static long getStringsLength(Collection<?> coll) {
        if (coll == null)
            return 0;
        long len = 0;
        for (Object o : coll)
            len += o.toString().length();
        return len;
    }

    private static String nullToEmpty(String s) {
        return s != null ? s : "";
    }

    private static String emptyToNull(String s) {
        if (s == null)
            return null;
        s = s.trim();
        return s.isEmpty() ? null : s;
    }

    private static <T> T xor(T x, T y) {
        assert x == null ^ y == null;
        return x != null ? x : y;
    }

    // visible for testing
    static List<String> parseCommandLineArguments(final String str) {
       /*
        * Modified from Ant's CommandLine parser
        * http://grepcode.com/file/repo1.maven.org/maven2/org.apache.ant/ant/1.9.5/org/apache/tools/ant/types/Commandline.java#Commandline.translateCommandline%28java.lang.String%29
        */
        if (str == null || str.length() == 0)
            return emptyList();

        final int NORMAL = 0,
                IN_QUOTE = 1,
                IN_DOUBLE_QUOTE = 2;
        
        final StringTokenizer tok = new StringTokenizer(str, "\"\'\\ ", true);
        final ArrayList<String> result = new ArrayList<>();
        final StringBuilder current = new StringBuilder();
        
        int state = NORMAL;
        boolean lastTokenHasBeenQuoted = false;
        while (tok.hasMoreTokens()) {
            final String nextTok = tok.nextToken();
            switch (state) {
                case IN_QUOTE:
                    if ("\'".equals(nextTok)) {
                        lastTokenHasBeenQuoted = true;
                        state = NORMAL;
                    } else
                        current.append(nextTok);
                    break;
                case IN_DOUBLE_QUOTE:
                    if ("\"".equals(nextTok)) {
                        lastTokenHasBeenQuoted = true;
                        state = NORMAL;
                    } else
                        current.append(nextTok);
                    break;
                default:
                    if ("\'".equals(nextTok))
                        state = IN_QUOTE;
                    else if ("\"".equals(nextTok))
                        state = IN_DOUBLE_QUOTE;
                    else if (" ".equals(nextTok)) {
                        if (lastTokenHasBeenQuoted || current.length() != 0) {
                            result.add(current.toString());
                            current.setLength(0);
                        }
                    } else
                        current.append(nextTok);
                    lastTokenHasBeenQuoted = false;
                    break;
            }
        }
        if (lastTokenHasBeenQuoted || current.length() != 0)
            result.add(current.toString());
        if (state == IN_QUOTE || state == IN_DOUBLE_QUOTE)
            throw new IllegalArgumentException("unbalanced quotes in " + str);
        return result;
    }

    @SuppressWarnings("fallthrough")
    static String globToRegex(String pattern) {
        // Based on Neil Traft: http://stackoverflow.com/a/17369948/750563
        final String DOT = "[^/]"; // "." -- exclude slashes
        final StringBuilder sb = new StringBuilder(pattern.length());
        int inGroup = 0;
        int inClass = 0;
        int firstIndexInClass = -1;
        char[] arr = pattern.toCharArray();
        for (int i = 0; i < arr.length; i++) {
            char ch = arr[i];
            switch (ch) {
                case '\\':
                    if (++i >= arr.length) {
                        sb.append('\\');
                    } else {
                        char next = arr[i];
                        switch (next) {
                            case ',':
                                // escape not needed
                                break;
                            case 'Q':
                            case 'E':
                                // extra escape needed
                                sb.append('\\');
                            default:
                                sb.append('\\');
                        }
                        sb.append(next);
                    }
                    break;
                case '*':
                    if (inClass == 0)
                        sb.append(DOT + "*");
                    else
                        sb.append('*');
                    break;
                case '?':
                    if (inClass == 0)
                        sb.append(DOT);
                    else
                        sb.append('?');
                    break;
                case '[':
                    inClass++;
                    firstIndexInClass = i + 1;
                    sb.append('[');
                    break;
                case ']':
                    inClass--;
                    sb.append(']');
                    break;
                case '.':
                case '(':
                case ')':
                case '+':
                case '|':
                case '^':
                case '$':
                case '@':
                case '%':
                    if (inClass == 0 || (firstIndexInClass == i && ch == '^'))
                        sb.append('\\');
                    sb.append(ch);
                    break;
                case '!':
                    if (firstIndexInClass == i)
                        sb.append('^');
                    else
                        sb.append('!');
                    break;
                case '{':
                    inGroup++;
                    sb.append('(');
                    break;
                case '}':
                    inGroup--;
                    sb.append(')');
                    break;
                case ',':
                    if (inGroup > 0)
                        sb.append('|');
                    else
                        sb.append(',');
                    break;
                default:
                    sb.append(ch);
            }
        }
        return sb.toString();
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Collection Utils">
    /////////// Collection Utils ///////////////////////////////////
    @SuppressWarnings("unchecked")
    private static <T> List<T> nullToEmpty(List<T> list) {
        return list != null ? list : (List<T>) emptyList();
    }

    @SuppressWarnings("unchecked")
    private static <K, V> Map<K, V> nullToEmpty(Map<K, V> map) {
        return map != null ? map : (Map<K, V>) emptyMap();
    }

    private static <T> List<T> emptyToNull(List<T> list) {
        return (list != null && !list.isEmpty()) ? list : null;
    }

    private static <K, V> Map<K, V> emptyToNull(Map<K, V> map) {
        return (map != null && !map.isEmpty()) ? map : null;
    }

//    private static <K, V> Map<K, List<V>> multiput(Map<K, List<V>> map, K key, V value) {
//        List<V> list = map.get(key);
//        if (list == null) {
//            list = new ArrayList<>();
//            map.put(key, list);
//        }
//        list.add(value);
//        return map;
//    }
//
    private static <K, V> Map<K, List<V>> multiput(Map<K, List<V>> map, K key, List<V> values) {
        if (values == null)
            return map;
        List<V> list = map.get(key);
        if (list == null) {
            list = new ArrayList<>();
            map.put(key, list);
        }
        list.addAll(values);
        return map;
    }

    private static <K, V> Map<K, List<V>> multiputAll(Map<K, List<V>> map, Map<K, List<V>> map2) {
        for (Map.Entry<K, List<V>> entry : map2.entrySet()) {
            List<V> list = map.get(entry.getKey());
            if (list == null) {
                list = new ArrayList<>();
                map.put(entry.getKey(), list);
            }
            list.addAll(entry.getValue());
        }
        return map;
    }

    private static boolean isEmpty(Iterable<?> c) {
        if (c instanceof Collection)
            return ((Collection<?>) c).isEmpty();
        final Iterator<?> it = c.iterator();
        return !it.hasNext();
    }

    private static boolean isDeepEmpty(Object o) {
        if (o == null)
            return true;
        else if ("".equals(o))
            return true;
        else if (o instanceof Path)
            return false; // special case: a path is an iterable that may contain itself
        else if (o instanceof Iterable) {
            for (Object x : (Iterable<?>) o) {
                if (!isDeepEmpty(x))
                    return false;
            }
            return true;
        } else
            return false;
    }

    private static <T> T first(Iterable<T> c) {
        if (c == null || isEmpty(c))
            throw new IllegalArgumentException("Not found");
        return (c instanceof List && c instanceof RandomAccess) ? ((List<T>) c).get(0) : c.iterator().next();
    }

    private static <T> T firstOrNull(Iterable<T> c) {
        if (c == null || isEmpty(c))
            return null;
        return (c instanceof List && c instanceof RandomAccess) ? ((List<T>) c).get(0) : c.iterator().next();
    }

    private static <T> T only(List<T> c) {
        if (c == null || c.isEmpty())
            throw new IllegalArgumentException("Not found");
        if (c.size() > 1)
            throw new IllegalArgumentException("Expected a single element but found " + c.size() + ": " + c);
        return c.get(0);
    }

    private static <C extends Collection<T>, T> C addAll(C c, Collection<T> c1) {
        if (c1 != null)
            c.addAll(c1);
        return c;
    }

    private static <C extends Collection<? super T>, T> C addAllIfAbsent(C c, Collection<T> c1) {
        if (c1 != null) {
            for (T e : c1) {
                if (!c.contains(e))
                    c.add(e);
            }
        }
        return c;
    }

    private static <M extends Map<K, V>, K, V> M putAllIfAbsent(M m, Map<K, V> m1) {
        for (Map.Entry<K, V> entry : m1.entrySet()) {
            if (!m.containsKey(entry.getKey()))
                m.put(entry.getKey(), entry.getValue());
        }
        return m;
    }

    private static <K, V> Entry<K, V> entry(K k, V v) {
        return new AbstractMap.SimpleImmutableEntry<K, V>(k, v);
    }

    private static <K, V> Entry<K, V> mutableEntry(K k, V v) {
        return new AbstractMap.SimpleEntry<K, V>(k, v);
    }

    @SafeVarargs
    private static <T> Set<T> immutableSet(T... elems) {
        return unmodifiableSet(new HashSet<T>(asList(elems)));
    }

    private static boolean isEmpty(Object x) {
        if (x == null)
            return true;
        if (x instanceof String)
            return ((String) x).isEmpty();
        if (x instanceof Collection)
            return ((Collection) x).isEmpty();
        if (x instanceof Map)
            return ((Map) x).isEmpty();
        return false;
    }

    @SuppressWarnings("unchecked")
    private static <T> T merge(T v1, T v2) {
        if (v2 == null)
            return v1;
        if (v1 instanceof Collection) {
            final Collection<Object> c1 = (Collection<Object>) v1;
            final Collection<Object> c2 = (Collection<Object>) v2;
            final Collection<Object> cm;
            if (v1 instanceof List)
                cm = new ArrayList<>(c1.size() + c2.size());
            else if (v1 instanceof Set)
                cm = new HashSet<>(c1.size() + c2.size());
            else
                throw new RuntimeException("Unhandled type: " + v1.getClass().getName());
            cm.addAll(c1);
            addAllIfAbsent(cm, c2);
            return (T) cm;
        } else if (v1 instanceof Map) {
            final Map<Object, Object> mm = new HashMap<>();
            mm.putAll((Map<Object, Object>) v1);
            mm.putAll((Map<Object, Object>) v2);
            return (T) mm;
        } else
            return v2;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Reflection Utils">
    /////////// Reflection Utils ///////////////////////////////////
    private static Method getMethod(Capsule capsule, String name, Class<?>... parameterTypes) throws NoSuchMethodException {
        for (Capsule c = capsule.cc; c != null; c = c.sup) {
            try {
                return getMethod(c.getClass(), name, parameterTypes);
            } catch (NoSuchMethodException e) {
            }
        }
        throw new NoSuchMethodException(name + "(" + Arrays.toString(parameterTypes) + ")");
    }

    private static Method getMethod(Class<?> clazz, String name, Class<?>... parameterTypes) throws NoSuchMethodException {
        try {
            return accessible(clazz.getDeclaredMethod(name, parameterTypes));
        } catch (NoSuchMethodException e) {
            if (clazz.getSuperclass() == null)
                throw new NoSuchMethodException(name + "(" + Arrays.toString(parameterTypes) + ")");
            return getMethod(clazz.getSuperclass(), name, parameterTypes);
        }
    }

    private static Method getMethod(Class<?> clazz, Method method) {
        if (clazz.equals(method.getDeclaringClass()))
            return method;
        try {
            return getMethod(clazz, method.getName(), method.getParameterTypes());
        } catch (NoSuchMethodException e) {
            return null;
        }
    }

    private static <T extends AccessibleObject> T accessible(T obj) {
        if (obj == null)
            return null;
        obj.setAccessible(true);
        return obj;
    }

    private static ClassLoader newClassLoader0(ClassLoader parent, List<Path> ps) {
        try {
            final List<URL> urls = new ArrayList<>(ps.size());
            for (Path p : ps)
                urls.add(p.toUri().toURL());
            return new URLClassLoader(urls.toArray(new URL[urls.size()]), parent);
        } catch (MalformedURLException e) {
            throw new AssertionError(e);
        }
    }

    private static ClassLoader newClassLoader0(ClassLoader parent, Path... ps) {
        return newClassLoader0(parent, asList(ps));
    }

    /**
     * For internal use; subject to change/removal.
     *
     * @deprecated exclude from javadocs
     */
    ClassLoader newClassLoader(ClassLoader parent, List<Path> ps) {
        return newClassLoader0(parent, ps);
    }

    private ClassLoader newClassLoader(ClassLoader parent, Path... ps) {
        return newClassLoader(parent, asList(ps));
    }

    private static boolean isStream(String className) {
        return className.startsWith("java.util.stream") || className.contains("$$Lambda") || className.contains("Spliterator");
    }

    private static boolean isThrows(Method method, Throwable t) {
        for (Class<?> etype : method.getExceptionTypes()) {
            if (etype.isInstance(t))
                return true;
        }
        return false;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Misc Utils">
    /////////// Misc Utils ///////////////////////////////////
    private static String propertyOrEnv(String propName, String envVar) {
        String val = getProperty(propName);
        if (val == null)
            val = emptyToNull(getenv(envVar));
        return val;
    }

    /**
     * Returns a system property - should be used instead of {@link System#getProperty(java.lang.String) System.getProperty(propName)}.
     */
    protected static final String getProperty(String propName) {
        final String val = getProperty0(propName);
        setContext("system property", propName, val);
        return val;
    }

    private static String getProperty0(String propName) {
        return propName != null ? PROPERTIES.getProperty(propName) : null;
    }

    /**
     * Sets a system property.
     */
    protected static final void setProperty(String propName, String value) {
        PROPERTIES.setProperty(propName, value);
    }

    /**
     * Returns the value of an environment variable - should be used instead of {@link System#getenv(java.lang.String) System.getenv(envName)}.
     */
    protected static String getenv(String envName) {
        final String val = envName != null ? System.getenv(envName) : null;
        setContext("environment variable", envName, val);
        return val;
    }

    private static boolean systemPropertyEmptyOrTrue(String property) {
        return emptyOrTrue(getProperty0(property));
    }

    private static boolean emptyOrTrue(String value) {
        if (value == null)
            return false;
        return value.isEmpty() || Boolean.parseBoolean(value);
    }

    private static boolean systemPropertyEmptyOrNotFalse(String property) {
        final String value = getProperty0(property);
        if (value == null)
            return false;
        return value.isEmpty() || !"false".equalsIgnoreCase(value);
    }

    private static Throwable deshadow(Throwable t) {
        return deshadow("capsule", t);
    }

    private static Throwable deshadow(String prefix, Throwable t) {
        prefix = prefix.endsWith(".") ? prefix : prefix + ".";
        final StackTraceElement[] st = t.getStackTrace();
        for (int i = 0; i < st.length; i++) {
            String className = st[i].getClassName();
            className = (className != null && className.startsWith(prefix) && className.lastIndexOf('.') > prefix.length())
                    ? className.substring(prefix.length()) : className;
            st[i] = new StackTraceElement(className, st[i].getMethodName(), st[i].getFileName(), st[i].getLineNumber());
        }
        t.setStackTrace(st);

        if (t.getCause() != null)
            deshadow(prefix, t.getCause());
        return t;
    }

    private static RuntimeException rethrow(Throwable t) {
        while (t instanceof InvocationTargetException)
            t = ((InvocationTargetException) t).getTargetException();
        if (t instanceof RuntimeException)
            throw (RuntimeException) t;
        if (t instanceof Error)
            throw (Error) t;
        throw new RuntimeException(t);
    }

    private static void close(Object c) {
        try {
            ((AutoCloseable) c).close();
        } catch (Exception ex) {
        }
    }

    private static boolean isAlive(Process p) {
        // return p.isAlive() // JDK8
        try {
            p.exitValue();
            return true;
        } catch (IllegalThreadStateException e) {
            return false;
        }
    }

    private static boolean waitFor(Process p, long millis) throws InterruptedException {
        // return p.waitFor(millis, TimeUnit.MILLISECONDS); // JDK 8
        final long deadline = System.nanoTime() + millis * 1_000_000;
        for (;;) {
            if (!isAlive(p))
                return true;
            long sleep = Math.min((deadline - System.nanoTime()) / 1_000_000, 20);
            if (sleep <= 0)
                return false;
            Thread.sleep(sleep);
        }
    }

    /**
     * Executes a command and returns its output as a list of lines.
     * The method will wait for the child process to terminate, and throw an exception if the command returns an exit value {@code != 0}.
     * <br>Same as calling {@code exec(-1, cmd}}.
     *
     * @param cmd the command
     * @return the lines output by the command
     */
    protected static Iterable<String> exec(String... cmd) throws IOException {
        return exec(-1, cmd);
    }

    /**
     * Executes a command and returns its output as a list of lines.
     * If the number of lines read is less than {@code numLines}, or if {@code numLines < 0}, then the method will wait for the child process
     * to terminate, and throw an exception if the command returns an exit value {@code != 0}.
     *
     * @param numLines the maximum number of lines to read, or {@code -1} for an unbounded number
     * @param cmd      the command
     * @return the lines output by the command
     */
    protected static Iterable<String> exec(int numLines, String... cmd) throws IOException {
        return exec(numLines, new ProcessBuilder(asList(cmd)));
    }

    /**
     * Executes a command and returns its output as a list of lines.
     * The method will wait for the child process to terminate, and throw an exception if the command returns an exit value {@code != 0}.
     * <br>Same as calling {@code exec(-1, pb}}.
     *
     * @param pb the {@link ProcessBuilder} that will be used to launch the command
     * @return the lines output by the command
     */
    protected static Iterable<String> exec(ProcessBuilder pb) throws IOException {
        return exec(-1, pb);
    }

    /**
     * Executes a command and returns its output as a list of lines.
     * If the number of lines read is less than {@code numLines}, or if {@code numLines < 0}, then the method will wait for the child process
     * to terminate, and throw an exception if the command returns an exit value {@code != 0}.
     *
     * @param numLines the maximum number of lines to read, or {@code -1} for an unbounded number
     * @param pb       the {@link ProcessBuilder} that will be used to launch the command
     * @return the lines output by the command
     */
    protected static Iterable<String> exec(int numLines, ProcessBuilder pb) throws IOException {
        return exec(numLines, false, pb);
    }

    private static Iterable<String> exec(int numLines, boolean error, ProcessBuilder pb) throws IOException {
        final List<String> lines = new ArrayList<>();
        final Process p = pb.start();

        final InputStream in = error ? p.getErrorStream() : p.getInputStream();
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(in, Charset.defaultCharset()))) {
            for (int i = 0; numLines < 0 || i < numLines; i++) {
                final String line = reader.readLine();
                if (line == null)
                    break;
                lines.add(line);
            }
        }
        try {
            if (numLines < 0 || lines.size() < numLines) {
                final int exitValue = p.waitFor();
                if (exitValue != 0)
                    throw new RuntimeException("Command '" + join(pb.command(), " ") + "' has returned " + exitValue);
            }
            return lines;
        } catch (InterruptedException e) {
            throw rethrow(e);
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Logging">
    /////////// Logging ///////////////////////////////////
    private static void setLogLevel(int level) {
        LOG_LEVEL = level;
    }

    /**
     * Capsule's log level
     */
    protected static final int getLogLevel() {
        final Integer level = LOG_LEVEL;
        return level != null ? level : LOG_NONE;
    }

    /**
     * Chooses and returns the capsules log level.
     */
    protected int chooseLogLevel() {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.chooseLogLevel() : chooseLogLevel0();
    }

    private int chooseLogLevel0() {
        String level = getProperty(PROP_LOG_LEVEL);
        if (level == null && oc.manifest != null)
            level = getAttribute(ATTR_LOG_LEVEL);
        return getLogLevel(level);
    }

    private static int getLogLevel(String level) {
        try {
            int l = Integer.parseInt(level);
            if (l < 0)
                throw new IllegalArgumentException("Unrecognized log level: " + level);
            return l;
        } catch (NumberFormatException e) {
        }
        if (level == null || level.isEmpty())
            level = "QUIET";
        switch (level.toUpperCase()) {
            case "NONE":
                return LOG_NONE;
            case "QUIET":
                return LOG_QUIET;
            case "VERBOSE":
                return LOG_VERBOSE;
            case "DEBUG":
            case "ALL":
                return LOG_DEBUG;
            default:
                throw new IllegalArgumentException("Unrecognized log level: " + level);
        }
    }

    /**
     * Tests if the given log level is currently being logged.
     */
    protected static final boolean isLogging(int level) {
        return level <= getLogLevel();
    }

    /**
     * Prints a message to stderr if the given log-level is being logged.
     */
    protected static final void log(int level, String str) {
        if (isLogging(level))
            STDERR.println((AGENT ? LOG_AGENT_PREFIX : LOG_PREFIX) + str);
    }

    /**
     * Prints the given exception's stack-trace to stderr if the given log-level is being logged.
     */
    protected static final void log(int level, Throwable t) {
        if (t != null && isLogging(level))
            t.printStackTrace(STDERR);
    }

    private static void println(String str) {
        log(LOG_QUIET, str);
    }

    private static boolean hasContext() {
        return contextType_ != null;
    }

    private static void clearContext() {
        setContext(null, null, null);
    }

    private static void setContext(String type, String key, Object value) {
//        STDERR.println("setContext: " + type + " " + key + " " + value);
//        Thread.dumpStack();

        if (contextType_ == null)
            return;
        contextType_.set(type);
        contextKey_.set(key);
        contextValue_.set(value != null ? value.toString() : null);
    }

    private static String getContext() {
        return contextType_.get() + " " + contextKey_.get() + ": " + contextValue_.get();
    }

    private static long clock() {
        return isLogging(PROFILE) ? System.nanoTime() : 0;
    }

    private static void time(String op, long start) {
        time(op, start, isLogging(PROFILE) ? System.nanoTime() : 0);
    }

    private static void time(String op, long start, long stop) {
        if (isLogging(PROFILE))
            log(PROFILE, "PROFILE " + op + " " + ((stop - start) / 1_000_000) + "ms");
    }

    /**
     * Called when an unhandled exception is thrown, to display error information to the user before shutting down.
     */
    protected void onError(Throwable t) {
        if ((_ct = getCallTarget(Capsule.class)) != null)
            _ct.onError(t);
        else
            onError0(t);
    }

    private void onError0(Throwable t) {
        printError(t, this);
    }

    /**
     * Prints a value to {@code System.err} and returns it.
     * Useful for debugging
     *
     * @param label a prefix label
     * @param x     the value to trace
     * @return {@code x}
     */
    protected static <T> T trace(String label, T x) {
        final String s;
        if (x == null)
            s = "null";
        else if (x.getClass().isArray()) {
            if (!x.getClass().getComponentType().isPrimitive())
                s = Arrays.deepToString((Object[]) x);
            else if (x.getClass().getComponentType().equals(boolean.class))
                s = Arrays.toString((boolean[]) x);
            else if (x.getClass().getComponentType().equals(char.class))
                s = Arrays.toString((char[]) x);
            else if (x.getClass().getComponentType().equals(byte.class))
                s = Arrays.toString((byte[]) x);
            else if (x.getClass().getComponentType().equals(short.class))
                s = Arrays.toString((short[]) x);
            else if (x.getClass().getComponentType().equals(int.class))
                s = Arrays.toString((int[]) x);
            else if (x.getClass().getComponentType().equals(long.class))
                s = Arrays.toString((long[]) x);
            else if (x.getClass().getComponentType().equals(float.class))
                s = Arrays.toString((float[]) x);
            else if (x.getClass().getComponentType().equals(double.class))
                s = Arrays.toString((double[]) x);
            else
                throw new AssertionError();
        } else
            s = x.toString();
        System.err.println("TRACE " + label + ": " + s);
        return x;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Windows">
    /////////// Windows ///////////////////////////////////
    @SuppressWarnings("unchecked")
    private <T> T windowsAttributes(Entry<String, T> attr, T value) {
        if (!isWindows())
            return value;

        if (ATTR_AGENT == attr) {
            return (T) Boolean.TRUE;
        }

        return value;
    }

    //<editor-fold defaultstate="collapsed" desc="Long Classpath - Pathing JAR">
    /////////// Long Classpath - Pathing JAR ///////////////////////////////////
    private List<Path> handleLongClasspath(List<Path> cp, int extra, List<?>... args) {
        if (!isWindows())
            return cp; // why work hard if we know the problem only exists on Windows?

        long len = extra + getStringsLength(cp) + cp.size();
        for (List<?> list : args)
            len += getStringsLength(list) + list.size();

        if (len >= getMaxCommandLineLength()) {
            log(LOG_DEBUG, "Command line length: " + len);
            if (isTrampoline())
                throw new RuntimeException("Command line too long and trampoline requested.");
            final Path pathingJar = addTempFile(createPathingJar(getTempDir(), cp));
            log(LOG_VERBOSE, "Writing classpath: " + cp + " to pathing JAR: " + pathingJar);
            return singletonList(pathingJar);
        } else
            return cp;
    }

    // visible for testing
    static Path createPathingJar(Path dir, List<Path> cp) {
        try {
            dir = dir.toAbsolutePath();
            final List<String> paths = createPathingClassPath(dir, cp);

            final Path pathingJar = Files.createTempFile(dir, "capsule_pathing_jar", ".jar");
            final Manifest man = new Manifest();
            man.getMainAttributes().putValue(ATTR_MANIFEST_VERSION, "1.0");
            man.getMainAttributes().putValue(ATTR_CLASS_PATH, join(paths, " "));
            new JarOutputStream(Files.newOutputStream(pathingJar), man).close();

            return pathingJar;
        } catch (IOException e) {
            throw new RuntimeException("Pathing JAR creation failed", e);
        }
    }

    private static List<String> createPathingClassPath(Path dir, List<Path> cp) {
        boolean allPathsHaveSameRoot = true;
        for (Path p : cp) {
            if (!dir.getRoot().equals(p.getRoot()))
                allPathsHaveSameRoot = false;
        }

        final List<String> paths = new ArrayList<>(cp.size());
        for (Path p : cp) { // In order to use the Class-Path attribute, we must either relativize the paths, or specifiy them as file URLs
            if (allPathsHaveSameRoot)
                paths.add(dir.relativize(p).toString());
            else
                paths.add(p.toUri().toString());
        }
        return paths;
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Pipe Streams (workaround for inheritIO bug)">
    /////////// Pipe Streams (workaround for inheritIO bug) ///////////////////////////////////
    private static boolean isInheritIoBug() {
        return isWindows() && compareVersions(System.getProperty(PROP_JAVA_VERSION), "1.8.0") < 0;
    }

    private void pipeIoStreams() {
        startThread("pipe-out", "pipeStreamOut");
        startThread("pipe-err", "pipeStreamErr");
        startThread("pipe-in", "pipeStreamIn");
    }

    private void pipeStreamOut() throws IOException {
        pipe(child.getInputStream(), STDOUT);
    }

    private void pipeStreamErr() throws IOException {
        pipe(child.getErrorStream(), STDERR);
    }

    private void pipeStreamIn() throws IOException {
        pipe(System.in, child.getOutputStream());
    }

    private void pipe(InputStream in, OutputStream out) throws IOException {
        try (OutputStream out1 = out) {
            final byte[] buf = new byte[1024];
            int read;
            while (-1 != (read = in.read(buf))) {
                out.write(buf, 0, read);
                out.flush();
            }
        }
    }
    //</editor-fold>
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="POSIX">
    /////////// POSIX ///////////////////////////////////
    private static int getPid(Process p) {
        try {
            java.lang.reflect.Field pidField = p.getClass().getDeclaredField("pid");
            pidField.setAccessible(true);
            return pidField.getInt(p);
        } catch (Exception e) {
            return -1;
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="JMX">
    /////////// JMX ///////////////////////////////////
    /**
     * The Capsule agent will invoke this method to start a JMX Server.
     * The default implementation creates a local JMX connector.
     *
     * For internal use; subject to change/removal.
     *
     * @return The JMX service URL that the parent Capsule process will use to connect and proxy JMX commands.
     *
     * @deprecated marked deprecated to exclude from javadoc
     */
    protected JMXServiceURL startJMXServer() {
        /*
        * https://github.com/openjdk-mirror/jdk7u-jdk/blob/master/src/share/classes/sun/management/Agent.java
        * https://github.com/openjdk-mirror/jdk7u-jdk/blob/master/src/share/classes/sun/management/jmxremote/ConnectorBootstrap.java
         */
        final String LOCAL_CONNECTOR_ADDRESS_PROP = "com.sun.management.jmxremote.localConnectorAddress";

        try {
            log(LOG_VERBOSE, "Starting JMXConnectorServer");
            final JMXServiceURL url;

            // final JMXConnectorServer jmxServer = JMXConnectorServerFactory.newJMXConnectorServer(new JMXServiceURL("rmi", null, 0), null, ManagementFactory.getPlatformMBeanServer());
            // jmxServer.start(); // prevents the app from shutting down (requires jmxServer.stop()). See ConnectorBootstrap.PermanentExporter
            // url = jmxServer.getAddress();
            final Properties agentProps = sun.misc.VMSupport.getAgentProperties();
            if (agentProps.get(LOCAL_CONNECTOR_ADDRESS_PROP) == null) {
                log(LOG_VERBOSE, "Starting management agent");
                sun.management.Agent.agentmain(null); // starts a JMXConnectorServer that does not prevent the app from shutting down
            }
            url = new JMXServiceURL((String) agentProps.get(LOCAL_CONNECTOR_ADDRESS_PROP));

            log(LOG_VERBOSE, "JMXConnectorServer started JMX at " + url);
            return url;
        } catch (Exception e) {
            log(LOG_VERBOSE, "JMXConnectorServer failed: " + e.getMessage());
            log(LOG_VERBOSE, e);
            return null;
        }
    }

    private MBeanServerConnection connectToJMX(JMXServiceURL url) {
        try {
            log(LOG_VERBOSE, "Connecting to JMX server at: " + url);
            final JMXConnector connect = JMXConnectorFactory.connect(url);
            final MBeanServerConnection mbsc = connect.getMBeanServerConnection();
            log(LOG_VERBOSE, "JMX Connection successful");
            oc.jmxConnection = mbsc;
            return mbsc;
        } catch (Exception e) {
            log(LOG_VERBOSE, "JMX Connection failed: " + e.getMessage());
            log(LOG_VERBOSE, e);
            return null;
        }
    }

    /**
     * Returns an {@link MBeanServerConnection} to the application's {@code MBeanServer}.
     * This method may only be called within {@link #liftoff() }.
     */
    protected final MBeanServerConnection getMBeanServerConnection() {
        verifyAgent(false);
        verifyAfterStage(STAGE_LAUNCH);
        synchronized (oc) {
            if (oc.jmxConnection == null) {
                try {
                    send(MESSAGE_START_JMX, null);
                    receive();
                } catch (IOException e) {
                    printError(LOG_QUIET, e);
                }
            }
            return oc.jmxConnection;
        }
    }

    private Object invokeMBeanServer(Method method, Object[] args) throws ReflectiveOperationException {
        final MBeanServerConnection conn = lifecycleStage >= STAGE_LAUNCH ? getMBeanServerConnection() : null;
        final MBeanServerConnection target = conn != null ? conn : origMBeanServer;
        final Method m;
        if ((m = getMethod(target.getClass(), method)) != null)
            return m.invoke(target, args);
        else if (method.getName().startsWith("getClassLoader"))
            return MY_CLASSLOADER;
        else
            throw new UnsupportedOperationException();
    }

    private void overridePlatformMBeanServer() {
        try {
            MBeanServer platformMBeanServer = ManagementFactory.getPlatformMBeanServer();
            
            if (platformMBeanServer instanceof com.sun.jmx.mbeanserver.JmxMBeanServer) {
                final MBeanServer interceptor = (MBeanServer) Proxy.newProxyInstance(MY_CLASSLOADER, new Class<?>[]{MBeanServer.class}, this);
                
                Field interceptorField = accessible(com.sun.jmx.mbeanserver.JmxMBeanServer.class.getDeclaredField("mbsInterceptor"));
//                this.origMBeanServer = ((com.sun.jmx.mbeanserver.JmxMBeanServer) platformMBeanServer).getMBeanServerInterceptor();
                this.origMBeanServer = (MBeanServer) interceptorField.get(platformMBeanServer);
//                ((com.sun.jmx.mbeanserver.JmxMBeanServer) platformMBeanServer).setMBeanServerInterceptor(interceptor);
                interceptorField.set(platformMBeanServer, interceptor);
            }
            // accessible(ManagementFactory.class.getDeclaredField("platformMBeanServer")).set(null, this);
        } catch (Throwable e) { // JDK 9 throws an IllegalAccessError
            log(LOG_VERBOSE, "Overriding platform MBeanServer failed: " + e.getMessage());
            log(LOG_VERBOSE, e);
//            throw rethrow(e);
        }
    }

    /**
     * @deprecated marked deprecated to exclude from javadoc
     */
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        try {
            final Object res;
            if (MBeanServerConnection.class.equals(method.getDeclaringClass()) || MBeanServer.class.equals(method.getDeclaringClass()))
                res = invokeMBeanServer(method, args);
            else
                throw new UnsupportedOperationException();
            if (isLogging(LOG_DEBUG))
                log(LOG_DEBUG, "Invoke " + method + " with args: " + Arrays.toString(args) + " => " + res);
            return res;
        } catch (InvocationTargetException e) {
            Throwable t = e.getCause();
            assert t instanceof RuntimeException || t instanceof Error || isThrows(method, t);
            log(LOG_DEBUG, "Exception while running method " + method + " with args: " + Arrays.toString(args) + ": " + t);
            log(LOG_DEBUG, t);
            throw e;
        } catch (Exception e) {
            log(LOG_VERBOSE, "Exception while running method " + method + " with args: " + Arrays.toString(args) + ": " + e);
            log(LOG_VERBOSE, e);
            throw e;
        }
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Object Methods">
    /////////// Object Methods ///////////////////////////////////
    /**
     * Throws a {@link CloneNotSupportedException}
     *
     * @deprecated marked deprecated to exclude from javadoc
     */
    @SuppressWarnings("CloneDoesntCallSuperClone")
    @Override
    protected final Object clone() throws CloneNotSupportedException {
        throw new CloneNotSupportedException();
    }

    /**
     * @deprecated marked deprecated to exclude from javadoc
     */
    @Override
    public final int hashCode() {
        return super.hashCode();
    }

    /**
     * @deprecated marked deprecated to exclude from javadoc
     */
    @Override
    public final boolean equals(Object obj) {
        return super.equals(obj);
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append(getClass().getName());
        if (isLogging(LOG_DEBUG))
            sb.append('@').append(Integer.toHexString(System.identityHashCode(this)));
        if (cc != oc) {
            sb.append('(');
            for (Capsule c = cc; c != null; c = c.sup) {
                sb.append(c.getClass().getName());
                if (isLogging(LOG_DEBUG))
                    sb.append('@').append(Integer.toHexString(System.identityHashCode(c)));
                sb.append(" ");
            }
            sb.delete(sb.length() - 1, sb.length());
            sb.append(')');
        }
        sb.append('[');
        sb.append(jarFile);
        if (getAppId() != null) {
            sb.append(", ").append(getAppId());
            sb.append(", ").append(getAttribute(ATTR_APP_CLASS) != null ? getAttribute(ATTR_APP_CLASS) : getAttribute(ATTR_APP_ARTIFACT));
        } else
            sb.append(", ").append("empty");
        if (getMode() != null)
            sb.append(", ").append("mode: ").append(getMode());
        sb.append(']');
        return sb.toString();
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Capsule Loading and Launching">
    /////////// Capsule Loading and Launching ///////////////////////////////////
    /**
     * Loads the wrapped capsule when this capsule is the wrapper.
     * Caplets can override this method to provide security.
     *
     * @param parent the
     */
    protected Capsule loadTargetCapsule(ClassLoader parent, Path jarFile) {
        return (_ct = getCallTarget(Capsule.class)) != null ? _ct.loadTargetCapsule(parent, jarFile) : loadTargetCapsule0(parent, jarFile);
    }

    private Capsule loadTargetCapsule0(ClassLoader parent, Path jar) {
        return newCapsule(newClassLoader(parent, jar), jar);
    }

    // visible for testing
    static Capsule newCapsule(ClassLoader cl, Path jarFile) {
        return (Capsule) newCapsule0(cl, jarFile);
    }

    private static Object newCapsule0(ClassLoader cl, Path jarFile) {
        try {
            final ClassLoader ccl = Thread.currentThread().getContextClassLoader();
            try {
                Thread.currentThread().setContextClassLoader(cl);
                return accessible(loadCapsule(cl, jarFile).getDeclaredConstructor(Path.class)).newInstance(jarFile);
            } finally {
                Thread.currentThread().setContextClassLoader(ccl);
            }
        } catch (IncompatibleClassChangeError e) {
            throw new RuntimeException("Caplet " + jarFile + " is not compatible with this capsule (" + VERSION + ")");
        } catch (InvocationTargetException e) {
            throw rethrow(e.getTargetException());
        } catch (ReflectiveOperationException e) {
            throw new RuntimeException("Could not instantiate capsule.", e);
        }
    }

    private Capsule newCapsule(Path jarFile, Capsule pred) {
        try {
            final ClassLoader ccl = Thread.currentThread().getContextClassLoader();
            try {
                final ClassLoader cl = newClassLoader(pred.getClass().getClassLoader(), jarFile);
                Thread.currentThread().setContextClassLoader(cl);
                return accessible(loadCapsule(cl, jarFile).getDeclaredConstructor(Path.class)).newInstance(jarFile);
            } finally {
                Thread.currentThread().setContextClassLoader(ccl);
            }
        } catch (IncompatibleClassChangeError e) {
            throw new RuntimeException("Caplet " + jarFile + " is not compatible with this capsule (" + VERSION + ")");
        } catch (InvocationTargetException e) {
            throw rethrow(e.getTargetException());
        } catch (ReflectiveOperationException e) {
            throw new RuntimeException("Could not instantiate capsule.", e);
        }
    }

    private static Capsule newCapsule(String capsuleClass, Capsule pred) {
        try {
            final Class<? extends Capsule> clazz = loadCapsule(Thread.currentThread().getContextClassLoader(), capsuleClass, capsuleClass);
            assert getActualCapsuleClass(clazz) == Capsule.class;
            return accessible(clazz.getDeclaredConstructor(Capsule.class)).newInstance(pred);
        } catch (IncompatibleClassChangeError e) {
            throw new RuntimeException("Caplet " + capsuleClass + " is not compatible with this capsule (" + VERSION + ")");
        } catch (InvocationTargetException e) {
            throw rethrow(e.getTargetException());
        } catch (ReflectiveOperationException e) {
            throw new RuntimeException("Could not instantiate capsule " + capsuleClass, e);
        }
    }

    private static Class<? extends Capsule> loadCapsule(ClassLoader cl, Path jarFile) {
        final String mainClassName = getMainClass(jarFile);
        if (mainClassName != null)
            return loadCapsule(cl, mainClassName, jarFile.toString());
        throw new RuntimeException(jarFile + " does not appear to be a valid capsule.");
    }

    @SuppressWarnings("unchecked")
    private static Class<? extends Capsule> loadCapsule(ClassLoader cl, String capsuleClass, String name) {
        try {
            log(LOG_DEBUG, "Loading capsule class " + capsuleClass + " using class loader " + toString(cl));
            final Class<?> clazz = cl.loadClass(capsuleClass);
            final Class<Capsule> c = getActualCapsuleClass(clazz);
            if (c == null)
                throw new RuntimeException(name + " does not appear to be a valid capsule.");

            if (c != Capsule.class) // i.e. it's the Capsule class but in a different classloader
                accessible(c.getDeclaredField("PROPERTIES")).set(null, new Properties(PROPERTIES));

            return (Class<? extends Capsule>) clazz;
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("Caplet " + capsuleClass + " not found.", e);
        } catch (NoSuchFieldException e) {
            throw new RuntimeException(name + " does not appear to be a valid capsule.");
        } catch (IncompatibleClassChangeError | ClassCastException e) {
            throw new RuntimeException("Caplet " + capsuleClass + " is not compatible with this capsule (" + VERSION + ")");
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }

    @SuppressWarnings("unchecked")
    private static Class<Capsule> getActualCapsuleClass(Class<?> clazz) {
        Class<?> c = clazz;
        while (c != null && !Capsule.class.getName().equals(c.getName()))
            c = c.getSuperclass();
        return (Class<Capsule>) c;
    }

    private static String getCapsuleVersion(Class<?> cls) {
        while (cls != null && !cls.getName().equals(Capsule.class.getName()))
            cls = cls.getSuperclass();
        return getClassVersion(cls);
    }
    
    private static String getClassVersion(Class<?> cls) {
        if (cls == null)
            return null;
        try {
            final Field f = cls.getDeclaredField("VERSION");
            return (String) f.get(null);
        } catch (Exception e) {
            return null;
        }
    }

    private static String toString(ClassLoader cl) {
        return cl == null ? "null"
                : cl.toString() + (cl instanceof URLClassLoader ? ("{" + Arrays.toString(((URLClassLoader) cl).getURLs()) + "}") : "")
                  + " --> " + toString(cl.getParent());
    }
    //</editor-fold>

    //<editor-fold defaultstate="collapsed" desc="Security">
    /////////// Security ///////////////////////////////////
    private Capsule unsafe(Capsule target) {
        if (target != null) {
            final SecurityManager security = System.getSecurityManager();
            if (security != null && !target.getClass().getProtectionDomain().implies(PERM_UNSAFE_OVERRIDE)) {
                log(LOG_DEBUG, "Unsafe target " + target + " skipped");
                target = null;
            }
        }
        return target;
    }
    //</editor-fold>
}