[Fix #45] Fix JarFile extraction utility (#46)

src/main/java/info/freelibrary/util/I18nObject.java

@@ -46,7 +46,8 @@ public I18nObject(final String aBundleName) {
      * @param aLocale The locale of the desired bundle.
      */
     public I18nObject(final String aBundleName, final Locale aLocale) {
-        myBundle = (I18nResourceBundle) ResourceBundle.getBundle(aBundleName.toLowerCase(aLocale));
+        myBundle = (I18nResourceBundle) ResourceBundle.getBundle(aBundleName.toLowerCase(aLocale),
+                new CustomBundleControl());
     }
 
     /**

src/main/java/info/freelibrary/util/JarUtils.java

@@ -5,10 +5,9 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.net.JarURLConnection;
-import java.net.MalformedURLException;
 import java.net.URL;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Paths;
 import java.util.Enumeration;
 import java.util.LinkedList;
@@ -24,15 +23,25 @@
  */
 public final class JarUtils {
 
+    /**
+     * A constant for the protocol of a Jar file.
+     */
+    public static final String JAR_URL_PROTOCOL = "jar:file://";
+
+    /**
+     * The delimiter between the Jar file and its path.
+     */
+    public static final String JAR_URL_DELIMITER = "!/";
+
     /**
      * The logger used by the Jar utilities.
      */
     private static final Logger LOGGER = LoggerFactory.getLogger(JarUtils.class, MessageCodes.BUNDLE);
 
     /**
-     * A constant for the protocol of a Jar file.
+     * The number of components in a Jar URL.
      */
-    private static final String JAR_URL_PROTOCOL = "jar:file://";
+    private static final int URL_COMPONENT_COUNT = 2;
 
     /**
      * Creates a new Jar utilities instance.
@@ -54,7 +63,7 @@ public static URL[] getJarURLs() throws IOException {
         for (final JarFile jarFile : ClasspathUtils.getJarFiles()) {
             try (jarFile) {
                 final Manifest manifest = jarFile.getManifest();
-                final URL jarURL = new URL(JAR_URL_PROTOCOL + jarFile.getName() + "!/");
+                final URL jarURL = new URL(JAR_URL_PROTOCOL + jarFile.getName() + JAR_URL_DELIMITER);
 
                 urlList.add(jarURL);
 
@@ -84,53 +93,74 @@ public static URL[] getJarURLs() throws IOException {
     }
 
     /**
-     * Extract a particular path from a supplied Jar file to a supplied {@link java.io.File} location.
+     * Extracts the supplied path from the supplied Jar file's URL to the supplied {@link java.io.File} location. This
+     * method closes the JarFile.
      *
-     * @param aJarFilePath A path to a Jar file from which to extract
-     * @param aFilePath The Jar file path of the file to extract
+     * @param aJarURL A Jar URL that contains the system file path of a Jar file and a subfile path
      * @param aDestDir The destination directory into which the file should be extracted
      * @throws IOException If there is an exception thrown while reading or writing the file
+     * @throws NoSuchFileException If the Jar file cannot be found at the supplied path
+     * @throws MalformedUrlException If the supplied URL does not also contain a subfile path
      */
-    public static void extract(final String aJarFilePath, final String aFilePath, final File aDestDir)
-            throws IOException {
-        File file;
-
-        try {
-            // Opening the URL connection just parses location, it doesn't really "open" in the I/O sense
-            final JarURLConnection connection = (JarURLConnection) new URL(aJarFilePath).openConnection();
+    public static void extract(final URL aJarURL, final File aDestDir) throws IOException {
+        final String[] jarURLParts = aJarURL.getFile().split(JAR_URL_DELIMITER);
+        final File jarFile;
 
-            file = new File(connection.getJarFileURL().getFile());
-        } catch (final MalformedURLException details) {
-            file = new File(aJarFilePath);
+        if (jarURLParts.length != URL_COMPONENT_COUNT) {
+            throw new MalformedUrlException(LOGGER.getMessage(MessageCodes.UTIL_072, aJarURL));
         }
 
-        extract(file, aFilePath, aDestDir);
+        jarFile = new File(jarURLParts[0].substring(aJarURL.getProtocol().length() + 4)); // Remove protocol
+        extract(jarFile, jarURLParts[1], aDestDir);
+    }
+
+    /**
+     * Extract the supplied path from the supplied Jar file to a supplied {@link java.io.File} location. This method
+     * closes the JarFile.
+     *
+     * @param aJarFilePath The path to a Jar file from which to extract
+     * @param aFilePath The Jar's file path of the file to extract
+     * @param aDestDir The destination directory into which the file should be extracted
+     * @throws IOException If there is an exception thrown while reading or writing the file
+     * @throws NoSuchFileException If the Jar file cannot be found at the supplied path
+     */
+    public static void extract(final String aJarFilePath, final String aFilePath, final File aDestDir)
+            throws IOException {
+        if (aJarFilePath.startsWith(JAR_URL_PROTOCOL)) {
+            extract(new URL(aJarFilePath + JAR_URL_DELIMITER + aFilePath), aDestDir);
+        } else {
+            extract(new File(aJarFilePath), aFilePath, aDestDir);
+        }
     }
 
     /**
-     * Extract a particular path from a supplied Jar file to a supplied {@link java.io.File} location.
+     * Extract the supplied path from the supplied Jar file to the supplied {@link java.io.File} location. This method
+     * closes the JarFile.
      *
      * @param aJarFile A Jar file from which to extract
-     * @param aFilePath The Jar file path of the file to extract
+     * @param aFilePath The Jar's file path of the file to extract
      * @param aDestDir The destination directory into which the file should be extracted
      * @throws IOException If there is an exception thrown while reading or writing the file
+     * @throws NoSuchFileException If the Jar file cannot be found at the supplied path
      */
     public static void extract(final File aJarFile, final String aFilePath, final File aDestDir) throws IOException {
         extract(new JarFile(aJarFile), aFilePath, aDestDir);
     }
 
     /**
-     * Extract a particular path from a supplied Jar file to a supplied {@link java.io.File} location.
+     * Extract a particular path from the supplied Jar file to a supplied {@link java.io.File} location. This method
+     * closes the JarFile.
      *
-     * @param aJarFile A Jar file from which to extract
-     * @param aFilePath The Jar file path of the file to extract
+     * @param aJarFile A Jar file from which to extract the supplied file path
+     * @param aFilePath The Jar's file path of the file to extract
      * @param aDestDir The destination directory into which the file should be extracted
      * @throws IOException If there is an exception thrown while reading or writing the file
+     * @throws NoSuchFileException If the Jar file cannot be found at the supplied path
      */
     public static void extract(final JarFile aJarFile, final String aFilePath, final File aDestDir) throws IOException {
-        final Enumeration<JarEntry> entries = aJarFile.entries();
-
         try (aJarFile) {
+            final Enumeration<JarEntry> entries = aJarFile.entries();
+
             while (entries.hasMoreElements()) {
                 final JarEntry entry = entries.nextElement();
                 final String entryName = entry.getName();
@@ -149,6 +179,25 @@ public static void extract(final JarFile aJarFile, final String aFilePath, final
                     }
                 }
             }
+        } // Close JarFile when done with it
+    }
+
+    /**
+     * Tests whether the supplied file path exists in the supplied Jar file. This method does not close the JarFile.
+     *
+     * @param aJarFile A jar file to search
+     * @param aFilePath A path for which to search
+     * @return True if the file path is found; else, false
+     */
+    public static boolean contains(final JarFile aJarFile, final String aFilePath) throws IOException {
+        final Enumeration<JarEntry> entries = aJarFile.entries();
+
+        while (entries.hasMoreElements()) {
+            if (entries.nextElement().getName().equals(aFilePath)) {
+                return true;
+            }
         }
+
+        return false;
     }
 }

src/main/java/info/freelibrary/util/LoggingConsumer.java

@@ -0,0 +1,32 @@
+
+package info.freelibrary.util;
+
+import java.util.function.Consumer;
+
+/**
+ * A consumer that logs any exceptions. This is not an ideal solution (as the PMD suppressions indicate), but it
+ * provides a generic way to handle exceptions thrown in lambdas.
+ *
+ * @param <T> The type that the function accepts
+ */
+@FunctionalInterface
+public interface LoggingConsumer<T> extends Consumer<T> {
+
+    @Override
+    @SuppressWarnings("PMD.AvoidCatchingGenericException")
+    default void accept(final T aType) {
+        try {
+            acceptLogs(aType);
+        } catch (final Exception details) {
+            LoggerFactory.getLogger(LoggingConsumer.class, MessageCodes.BUNDLE).error(details, details.getMessage());
+        }
+    }
+
+    /**
+     * A method that logs any exceptions thrown by the consumer.
+     *
+     * @param aType A type being accepted by the consumer
+     */
+    void acceptLogs(T aType);
+
+}

src/main/java/info/freelibrary/util/ThrowingConsumer.java

@@ -0,0 +1,34 @@
+
+package info.freelibrary.util;
+
+import java.util.function.Consumer;
+
+/**
+ * A consumer that throws a runtime exception. This is not an ideal solution (as the PMD suppressions indicate), but it
+ * provides a generic way to handle exceptions thrown in lambdas.
+ *
+ * @param <T> The type that the function accepts
+ */
+@FunctionalInterface
+public interface ThrowingConsumer<T> extends Consumer<T> {
+
+    @Override
+    @SuppressWarnings("PMD.AvoidCatchingGenericException")
+    default void accept(final T aType) {
+        try {
+            acceptThrows(aType);
+        } catch (final Exception details) {
+            throw new I18nRuntimeException(details);
+        }
+    }
+
+    /**
+     * A method that wraps any exceptions through by the consumer with a runtime exception.
+     *
+     * @param aType A type being accepted by the consumer
+     * @throws Exception An exception thrown by the consumer
+     */
+    @SuppressWarnings("PMD.SignatureDeclareThrowsException")
+    void acceptThrows(T aType) throws Exception;
+
+}

src/main/java/info/freelibrary/util/warnings/PMD.java

@@ -88,6 +88,36 @@ public final class PMD {
      */
     public static final String UNUSED_PRIVATE_METHOD = "PMD.UnusedPrivateMethod";
 
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_design.html#cognitivecomplexity
+     */
+    public static final String COGNITIVE_COMPLEXITY = "PMD.CognitiveComplexity";
+
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_performance.html#avoidfilestream
+     */
+    public static final String AVOID_FILE_STREAM = "PMD.AvoidFileStream";
+
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_errorprone.html#avoidliteralsinifcondition
+     */
+    public static final String AVOID_LITERALS_IN_IF_CONDITION = "PMD.AvoidLiteralsInIfCondition";
+
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_errorprone.html#morethanonelogger
+     */
+    public static final String MORE_THAN_ONE_LOGGER = "PMD.MoreThanOneLogger";
+
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_performance.html#consecutiveliteralappends
+     */
+    public static final String CONSECUTIVE_LITERAL_APPENDS = "PMD.ConsecutiveLiteralAppends";
+
+    /**
+     * Cf. https://pmd.github.io/latest/pmd_rules_java_errorprone.html#avoidduplicateliterals
+     */
+    public static final String AVOID_DUPLICATE_LITERALS = "PMD.AvoidDuplicateLiterals";
+
     /*
      * Constant classes have private constructors.
      */

src/main/resources/freelib-utils_messages.xml

@@ -81,5 +81,6 @@
   <entry key="UTIL-069">The start index position ({}) is after the end position ({})</entry>
   <entry key="UTIL-070">Start position out of bounds: {}</entry>
   <entry key="UTIL-071">End position out of bounds: {}</entry>
+  <entry key="UTIL-072">Jar file's URL must contain a subfile path too: {}</entry>
 
 </properties>

src/test/java/info/freelibrary/util/I18nObjectTest.java

@@ -1,7 +1,9 @@
 
 package info.freelibrary.util;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.File;
 import java.io.IOException;
@@ -165,4 +167,12 @@ public void testHasI18nKey() {
         assertTrue(i18nObj.hasI18nKey(TEST_ONE));
         assertEquals(ONE, i18nObj.getI18n(TEST_ONE));
     }
+
+    /**
+     * Tests the use of an I18n properties file.
+     */
+    @Test
+    public void testPropertiesFile() {
+        assertEquals(1, new I18nObjectWrapper("test_messages").countKeys());
+    }
 }