ReflectionUtils.java

package org.bimserver.utils;

/******************************************************************************
 * Copyright (C) 2009-2014  BIMserver.org
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *****************************************************************************/

import java.io.File;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class ReflectionUtils {
	@SuppressWarnings({ "unchecked", "rawtypes" })
	public static <A> List<Class<A>> getClassesAsList(String pckgname, Class<A> type)
			throws ClassNotFoundException {
		ArrayList<Class<A>> classes = new ArrayList<Class<A>>();
		File directory = null;
		try {
			ClassLoader cld = Thread.currentThread().getContextClassLoader();
			if (cld == null) {
				throw new ClassNotFoundException("Can't get class loader.");
			}
			String path = pckgname.replace('.', '/');
			URL resource = cld.getResource(path);
			if (resource == null) {
				throw new ClassNotFoundException("No resource for " + path);
			}
			directory = new File(resource.getFile());
		} catch (NullPointerException x) {
			throw new ClassNotFoundException(pckgname + " (" + directory
					+ ") does not appear to be a valid package");
		}
		if (directory.exists()) {
			String[] files = directory.list();
			for (int i = 0; i < files.length; i++) {
				if (files[i].endsWith(".class")) {
					Class forName = Class.forName(pckgname + '.' + files[i].substring(0, files[i].length() - 6));
					if (type.isAssignableFrom(forName) && type != forName) {
						classes.add(forName);
					}
				}
			}
		} else {
			throw new ClassNotFoundException(pckgname
					+ " does not appear to be a valid package");
		}
		return classes;
	}
}