/*******************************************************************************
 * Copyright 2014 Rafael Garcia Moreno.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.bladecoder.engineeditor.common;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

/**
 * Class to support adding files to the current classpath when the application is running.
 * 
 *  This is useful to execute external classes inside the current VM.
 * 
 * @author rgarcia
 */
public class DinamicClassPath {

	@SuppressWarnings("rawtypes")
	private static final Class[] parameters = new Class[] { URL.class };

	public static void addFile(String s) throws IOException {
		File f = new File(s);
		addFile(f);
	}

	public static void addFile(File f) throws IOException {
		addURL(f.toURI().toURL());
	}

	public static void addURL(URL u) throws IOException {

		URLClassLoader sysloader = (URLClassLoader) ClassLoader
				.getSystemClassLoader();
		Class<URLClassLoader> sysclass = URLClassLoader.class;

		try {
			Method method = sysclass.getDeclaredMethod("addURL", parameters);
			method.setAccessible(true);
			method.invoke(sysloader, new Object[] { u });
		} catch (Throwable t) {
			t.printStackTrace();
			throw new IOException(
					"Error, could not add URL to system classloader");
		}

	}

}