Added proper usage instructions for new argument parsing policy

src/main/java/org/update4j/service/DefaultBootstrap.java

@@ -21,6 +21,7 @@
 import java.io.Reader;
 import java.io.Writer;
 import java.net.URL;
+import java.net.URLConnection;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -34,7 +35,6 @@
 import org.update4j.Configuration;
 import org.update4j.SingleInstanceManager;
 import org.update4j.Update;
-import org.update4j.util.StringUtils;
 
 public class DefaultBootstrap implements Delegate {
 
@@ -151,7 +151,7 @@ private void parseArgs(List<String> bootArgs) {
 			} else if (arg.equals("--delegate")) {
 				i++;
 				validateHasValue("delegate", bootArgs, i);
-				continue; // ignore
+				continue; // just ignore
 			}
 
 			Matcher m = Pattern.compile("--remote" + PATTERN).matcher(arg);
@@ -192,8 +192,8 @@ private void validateNotSet(String val, String command) {
 			throw new IllegalArgumentException("Duplicate --" + command + " command.");
 	}
 
-	private void validateHasValue(String argName, List<?> list, int index) {
-		if (index == list.size()) {
+	private void validateHasValue(String argName, List<String> list, int index) {
+		if (index >= list.size() || list.get(index).startsWith("--")) {
 			throw new IllegalArgumentException("Missing value for \"--" + argName + "\".");
 		}
 	}
@@ -203,7 +203,7 @@ private void updateFirst(List<String> args) throws Throwable {
 		Configuration localConfig = null;
 
 		if (remote != null) {
-			try (Reader in = new InputStreamReader(new URL(remote).openStream())) {
+			try (Reader in = openConnection(new URL(remote))) {
 				remoteConfig = getConfig(in);
 			}
 		}
@@ -264,7 +264,7 @@ private void launchFirst(List<String> args) throws Throwable {
 
 		Configuration remoteConfig = null;
 		if (remote != null) {
-			try (Reader in = new InputStreamReader(new URL(remote).openStream())) {
+			try (Reader in = openConnection(new URL(remote))) {
 				remoteConfig = getConfig(in);
 			}
 		}
@@ -300,6 +300,20 @@ private void launchFirst(List<String> args) throws Throwable {
 		}
 
 	}
+
+	private Reader openConnection(URL url) throws IOException {
+
+		URLConnection connection = url.openConnection();
+
+		// Some downloads may fail with HTTP/403, this may solve it
+		connection.addRequestProperty("User-Agent", "Mozilla/5.0");
+		// Set a connection timeout of 10 seconds
+		connection.setConnectTimeout(10 * 1000);
+		// Set a read timeout of 10 seconds
+		connection.setReadTimeout(10 * 1000);
+
+		return new InputStreamReader(connection.getInputStream());
+	}
 
 	private Configuration getConfig(Reader in) {
 		try {
@@ -321,7 +335,7 @@ private Configuration getConfig(Reader in) {
 	private static void welcome() {
 
 		System.out.println(getLogo() + "\tWelcome to the update4j framework.\n\n"
-				+ "\tYou started the framework with its default settings, which does\n"
+				+ "\tYou started the framework with its default bootstrap, which does\n"
 				+ "\tthe update and launch logic for you without complex setup. All you need is to\n"
 				+ "\tspecify some settings via command line arguments.\n\n"
 				+ "\tBefore you start, you first need to create a \"configuration\" file that contains\n"
@@ -332,17 +346,18 @@ private static void welcome() {
 				+ "\thttp://docs.update4j.org/javadoc/update4j/org/update4j/Configuration.html\n\n"
 				+ "\tWhile the default bootstrap works perfectly for a majority of cases, you might\n"
 				+ "\tfurther customize the update and launch life-cycle to the last detail by\n"
+				+ "\timplementing a custom bootstrap and update/launch your business application\n"
 				+ "\tusing the Configuration.update() and Configuration.launch() methods.\n\n"
 				+ "\tIf you choose to implement your own bootstrap, there are 2 ways to do it:\n\n"
 				+ "\t\t- Standard Mode: Start the bootstrap application using your own main method.\n"
 				+ "\t\t  You will not be able to update the bootstrap application (as code cannot update itself),\n"
 				+ "\t\t  only the business application will be updatable.\n\n"
 				+ "\t\t- Delegate Mode: Move your main method into an implementation of Delegate\n"
-				+ "\t\t  and start the framework just as you did now, i.e. calling \"update4j's\" main method.\n"
+				+ "\t\t  and start the framework just as you did now, i.e. calling *update4j's* main method.\n"
 				+ "\t\t  This allows you to update the bootstrap application by releasing a newer version\n"
 				+ "\t\t  with a higher version() number and make it visible to the JVM boot classpath\n"
 				+ "\t\t  or modulepath by placing it in the right directory.\n"
-				+ "\t\t  It it recommended not to use this feature before you can get everything\n"
+				+ "\t\t  It is recommended not to use this feature before you can get everything\n"
 				+ "\t\t  to run smoothly in Standard Mode, as this adds an extra layer of complexity.\n\n"
 				+ "\tFor more details about implementing the bootstrap, please refer to the Github wiki:\n"
 				+ "\thttps://github.com/update4j/update4j/wiki/Documentation#lifecycle\n"
@@ -356,8 +371,11 @@ private static String getLogo() {
 
 		return
 
-		"\n" + "\t                 _       _          ___ _ \n" + "\t                | |     | |        /   (_)\n"
-				+ "\t _   _ _ __   __| | __ _| |_ ___  / /| |_ \n" + "\t| | | | '_ \\ / _` |/ _` | __/ _ \\/ /_| | |\n"
+		"\n"
+				+ "\t                 _       _          ___ _ \n"
+				+ "\t                | |     | |        /   (_)\n"
+				+ "\t _   _ _ __   __| | __ _| |_ ___  / /| |_ \n"
+				+ "\t| | | | '_ \\ / _` |/ _` | __/ _ \\/ /_| | |\n"
 				+ "\t| |_| | |_) | (_| | (_| | ||  __/\\___  | |\n"
 				+ "\t \\__,_| .__/ \\__,_|\\__,_|\\__\\___|    |_/ |\n"
 				+ "\t      | |                             _/ |\n"
@@ -369,20 +387,25 @@ private static String getLogo() {
 
 	private static void usage() {
 
-		System.err.println("To start in modulepath:\n\n" + "\tjava -p update4j-" + Bootstrap.VERSION
-				+ ".jar -m org.update4j [commands...]\n" + "\tjava -p . -m org.update4j [commands...]\n\n"
-				+ "To start in classpath:\n\n" + "\tjava -jar update4j-" + Bootstrap.VERSION + ".jar [commands...]\n"
-				+ "\tjava -cp update4j-" + Bootstrap.VERSION + ".jar org.update4j.Bootstrap [commands...]\n"
-				+ "\tjava -cp * org.update4j.Bootstrap [commands...]\n\n" + "Available commands:\n\n"
-				+ "\t--remote=[url] - The remote (or if using file:/// scheme - local) location of the\n"
+		System.err.println("To start in modulepath:\n\n"
+				+ "\tjava -p update4j-" + Bootstrap.VERSION
+				+ ".jar -m org.update4j [commands...] [-- business-args...]\n"
+				+ "\tjava -p . -m org.update4j [commands...] [-- business-args...]\n\n"
+				+ "To start in classpath:\n\n" + "\tjava -jar update4j-"
+				+ Bootstrap.VERSION + ".jar [commands...] [-- business-args...]\n"
+				+ "\tjava -cp update4j-" + Bootstrap.VERSION
+				+ ".jar org.update4j.Bootstrap [commands...] [-- business-args...]\n"
+				+ "\tjava -cp * org.update4j.Bootstrap [commands...] [-- business-args...]\n\n"
+				+ "Available commands:\n\n"
+				+ "\t--remote [url] - The remote (or if using file:/// scheme - local) location of the\n"
 				+ "\t\tconfiguration file. If it fails to download or command is missing, it will\n"
 				+ "\t\tfall back to local.\n\n"
-				+ "\t--local=[path] - The path of a local configuration to use if the remote failed to download\n"
+				+ "\t--local [path] - The path of a local configuration to use if the remote failed to download\n"
 				+ "\t\tor was not passed. If both remote and local fail, startup fails.\n\n"
-				+ "\t--syncLocal - Sync the local configuration with the remote if it downloaded successfully.\n"
-				+ "\t\tUseful to still allow launching without Internet connection. Default will not sync unless\n"
-				+ "\t\t--launchFirst was specified.\n\n"
-				+ "\t--cert=[path] - A path to an X.509 certificate file to use to verify signatures. If missing,\n"
+				+ "\t--syncLocal - Sync the local configuration with the remote if it downloaded, loaded and\n"
+				+ "\t\tupdated files successfully. Useful to still allow launching without Internet connection.\n"
+				+ "\t\tDefault will not sync unless --launchFirst was specified.\n\n"
+				+ "\t--cert [path] - A path to an X.509 certificate file to use to verify signatures. If missing,\n"
 				+ "\t\tno signature verification will be performed.\n\n"
 				+ "\t--launchFirst - If specified, it will first launch the local application then silently\n"
 				+ "\t\tdownload the update; the update will be available only on next restart. It will still\n"
@@ -395,7 +418,8 @@ private static void usage() {
 				+ "\t\tand failed.\n\n"
 				+ "\t--singleInstance - Run the application as a single instance. Any subsequent attempts\n"
 				+ "\t\tto run will just exit. You can better control this feature by directly using the\n"
-				+ "\t\tSingleInstanceManager class.\n");
+				+ "\t\tSingleInstanceManager class.\n\n\n"
+				+ "To pass arguments to the business application, separate them with '--' (w/o quotes).");
 
 	}
 }