JspcMojoClassLoader.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.codehaus.mojo.jspc;

import java.net.URL;
import java.net.URLClassLoader;

/**
 * Custom class loader for the Jsp Compiler.
 *
 * @version $Id$
 */
public class JspcMojoClassLoader
    extends URLClassLoader
{
    private ClassLoader parent;

    public JspcMojoClassLoader() {
        this(ClassLoader.getSystemClassLoader());
    }

    public JspcMojoClassLoader(ClassLoader parent) {
        super(new URL[0]);
        
        this.parent = parent;
    }

    public void addURL(URL url) {
        super.addURL(url);
    }

    public URL findResource(String name) {
        URL url = super.findResource(name);
        
        if (url == null){
            url = parent.getResource(name);
        }
        
        return url;
    }

    public synchronized Class loadClass(String className) throws ClassNotFoundException {
        Class c = findLoadedClass(className);

        ClassNotFoundException ex = null;

        if (c == null) {
            try {
                c = super.loadClass(className);
            }
            catch (ClassNotFoundException e) {
                ex = e;

                if (parent != null) {
                    c = parent.loadClass(className);
                }
            }
        }

        if (c == null) {
            throw ex;
        }

        return c;
    }
}