Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.lang.reflect.Method;
import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

public class Main {

    /**
     * Format a string buffer containing the Class, Interfaces, CodeSource, and
     * ClassLoader information for the given object clazz.
     * 
     * @param clazz
     *          the Class
     * @param results -
     *          the buffer to write the info to
     */
    public static void displayClassInfo(Class clazz, StringBuffer results) {
        // Print out some codebase info for the clazz
        ClassLoader cl = clazz.getClassLoader();
        results.append("\n");
        results.append(clazz.getName());
        results.append("(");
        results.append(Integer.toHexString(clazz.hashCode()));
        results.append(").ClassLoader=");
        results.append(cl);
        ClassLoader parent = cl;
        while (parent != null) {
            results.append("\n..");
            results.append(parent);
            URL[] urls = getClassLoaderURLs(parent);
            int length = urls != null ? urls.length : 0;
            for (int u = 0; u < length; u++) {
                results.append("\n....");
                results.append(urls[u]);
            }
            if (parent != null)
                parent = parent.getParent();
        }
        CodeSource clazzCS = clazz.getProtectionDomain().getCodeSource();
        if (clazzCS != null) {
            results.append("\n++++CodeSource: ");
            results.append(clazzCS);
        } else
            results.append("\n++++Null CodeSource");

        results.append("\nImplemented Interfaces:");
        Class[] ifaces = clazz.getInterfaces();
        for (int i = 0; i < ifaces.length; i++) {
            Class iface = ifaces[i];
            results.append("\n++");
            results.append(iface);
            results.append("(");
            results.append(Integer.toHexString(iface.hashCode()));
            results.append(")");
            ClassLoader loader = ifaces[i].getClassLoader();
            results.append("\n++++ClassLoader: ");
            results.append(loader);
            ProtectionDomain pd = ifaces[i].getProtectionDomain();
            CodeSource cs = pd.getCodeSource();
            if (cs != null) {
                results.append("\n++++CodeSource: ");
                results.append(cs);
            } else
                results.append("\n++++Null CodeSource");
        }
    }

    /**
     * Use reflection to access a URL[] getURLs or URL[] getClasspath method so
     * that non-URLClassLoader class loaders, or class loaders that override
     * getURLs to return null or empty, can provide the true classpath info.
     * 
     * @param cl
     * @return the urls
     */
    public static URL[] getClassLoaderURLs(ClassLoader cl) {
        URL[] urls = {};
        try {
            Class returnType = urls.getClass();
            Class[] parameterTypes = {};
            Class clClass = cl.getClass();
            Method getURLs = clClass.getMethod("getURLs", parameterTypes);
            if (returnType.isAssignableFrom(getURLs.getReturnType())) {
                Object[] args = {};
                urls = (URL[]) getURLs.invoke(cl, args);
            }
            if (urls == null || urls.length == 0) {
                Method getCp = clClass.getMethod("getClasspath", parameterTypes);
                if (returnType.isAssignableFrom(getCp.getReturnType())) {
                    Object[] args = {};
                    urls = (URL[]) getCp.invoke(cl, args);
                }
            }
        } catch (Exception ignore) {
        }
        return urls;
    }
}