ClassFileReader.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.apache.axis2.tool.codegen.eclipse.util;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.util.List;
import java.security.PrivilegedAction;

/**
 * A utility class for reading/loading classes and
 * extracting the information.
 *
 */
public class ClassFileReader {

	/**
	 * try whether a given class can be loaded from the given location
	 * @param className
	 * @param classPathEntries
	 * @param errorListener
	 * @return
	 */
	public static boolean tryLoadingClass(String className,
			String[] classPathEntries, List errorListener) {
		//make a URL class loader from the entries
		ClassLoader classLoader;

		if (classPathEntries.length > 0) {
			final URL[] urls = new URL[classPathEntries.length];

			try {
				for (int i = 0; i < classPathEntries.length; i++) {
					String classPathEntry = classPathEntries[i];
					//this should be a file(or a URL)
					if (classPathEntry.startsWith("http://")) {
						urls[i] = new URL(classPathEntry);
					} else {
						urls[i] = new File(classPathEntry).toURL();
					}
				}
			} catch (MalformedURLException e) {
				if (errorListener!=null){
					errorListener.add(e);
				}
				return false;
			}

			classLoader = AccessController.doPrivileged(new PrivilegedAction<URLClassLoader>() {
				public URLClassLoader run() {
					return new URLClassLoader(urls);
				}
			});

		} else {
			classLoader = Thread.currentThread().getContextClassLoader();
		}
		
		//try to load the class with the given name
		
		try {
			Class clazz=classLoader.loadClass(className);
			clazz.getMethods();
		    
			
		} catch (Throwable t) {
			if (errorListener!=null){
				errorListener.add(t);
			}
			return false;
		}

		return true;

	}

}