ClassLoader Test

public static void main(String[] args) {
		String pkgs = "com";
		loadByClassLoader(pkgs);
		//loadByResolverUtil();
	}
	public static void loadByResolverUtil(String pkgs){
		ResolverUtil<Class> resolver = new ResolverUtil<Class>();
		resolver.findInPackage(new Test() {
			public boolean matches(Class type) {
				// TODO: should also find annotated classes
				// return (Action.class.isAssignableFrom(type) ||
				// type.getSimpleName().endsWith("Action"));
				return true;
			}
		}, pkgs);
		System.out.println(resolver.getClasses().size());
		for (Class<?> actionClass : resolver.getClasses()) {
			System.out.println(actionClass.getName());
		}
	}
	public static void loadByClassLoader(String pkgs) {
		
		ClassLoader loader = ClassLoader.getSystemClassLoader();
		Enumeration<URL> urls;
		try {
			urls = loader.getResources(pkgs);
			while (urls.hasMoreElements()) {
				String urlPath = urls.nextElement().getFile();
				// urlPath = URLDecoder.decode(urlPath, "UTF-8");

				// If it's a file in a directory, trim the stupid file: spec
				if (urlPath.startsWith("file:"))
					urlPath = urlPath.substring(5);

				// Else it's in a JAR, grab the path to the jar
				if (urlPath.indexOf('!') > 0)
					urlPath = urlPath.substring(0, urlPath.indexOf('!'));

				// log.info("Scanning for classes in [" + urlPath + "] matching
				// criteria: " + test);
				File file = new File(urlPath);
				if (file.isDirectory())
					loadImplementationsInDirectory(pkgs, file);
				else
					loadImplementationsInJar(pkgs, file);
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public static void loadImplementationsInDirectory(String parent, File location) {
		File[] files = location.listFiles();
		StringBuilder builder = null;

		for (File file : files) {
			builder = new StringBuilder(100);
			builder.append(parent).append("/").append(file.getName());
			String packageOrClass = (parent == null ? file.getName() : builder.toString());

			if (file.isDirectory())
				loadImplementationsInDirectory(packageOrClass, file);
			else if (file.getName().endsWith(".class"))
				addIfMatching(packageOrClass);
		}
	}

	/**
	 * Finds matching classes within a jar files that contains a folder
	 * structure matching the package structure. If the File is not a JarFile or
	 * does not exist a warning will be logged, but no error will be raised.
	 * 
	 * @param test
	 *            a Test used to filter the classes that are discovered
	 * @param parent
	 *            the parent package under which classes must be in order to be
	 *            considered
	 * @param jarfile
	 *            the jar file to be examined for classes
	 */
	public static void loadImplementationsInJar(String parent, File jarfile) {

		try {
			JarEntry entry;
			JarInputStream jarStream = new JarInputStream(new FileInputStream(jarfile));

			while ((entry = jarStream.getNextJarEntry()) != null) {
				String name = entry.getName();
				if (!entry.isDirectory() && name.startsWith(parent) && name.endsWith(".class"))
					addIfMatching(name);
			}
		} catch (IOException ioe) {
			System.out.println("Could not search jar file '" + jarfile + "' for classes matching criteria: " + " due to an IOException");
		}
	}

	public static void addIfMatching(String fqn) {
		try {
			String externalName = fqn.substring(0, fqn.indexOf('.')).replace('/', '.');
			ClassLoader loader = ClassLoader.getSystemClassLoader();
			/*
			 * if (log.isDebugEnabled()) { log.debug("Checking to see if class " +
			 * externalName + " matches criteria [" + test + "]"); }
			 */

			Class type = loader.loadClass(externalName);
			System.out.println(type.getName());
		} catch (Throwable t) {
			System.out.println("Could not examine class '" + fqn + "' due to a " + t.getClass().getName() + " with message: " + t.getMessage());
		}
	}