001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.osgi.application;
023
024import java.io.File;
025import java.io.IOException;
026import java.lang.reflect.Method;
027import java.net.URL;
028import java.net.URLClassLoader;
029import java.util.ArrayList;
030import java.util.List;
031
032/**
033 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
034 */
035public class Main {
036
037    public static void main(String[] args) throws Exception {
038        if (args.length == 0) {
039            System.err.println("No classpath specified");
040            System.exit(10);
041        }
042        ClassLoader cl = Thread.currentThread().getContextClassLoader();
043        if (!(cl instanceof URLClassLoader)) {
044            System.err.println("Not a valid class loader: " + cl);
045            System.exit(10);
046        }
047        ClassLoader parent = cl.getParent();
048        if (parent == null) {
049            parent = ClassLoader.getSystemClassLoader();
050        }
051        RootClassLoader rootLoader = new RootClassLoader(parent, SharedClassLoader.class);
052        SharedClassLoaderImpl classLoader = new SharedClassLoaderImpl(((URLClassLoader) cl).getURLs(), rootLoader);
053        Thread.currentThread().setContextClassLoader(classLoader.getLoader());
054        URL systemBundle = classLoader.getURLs()[0];
055        // build the class path now
056        List<File> cp = buildClassPath(classLoader, args[0]);
057        // make new arguments by removing the first one to pass further
058        String[] tmp = new String[args.length - 1];
059        System.arraycopy(args, 1, tmp, 0, tmp.length);
060        args = tmp;
061        // reload classes from this JAR using a SharedClassLoader
062        Class<?> me = classLoader.loadClass(StandaloneApplication.class.getName());
063        Method main = me.getMethod("main", URL.class, List.class, String[].class);
064        main.invoke(null, systemBundle, cp, args);
065    }
066
067    public static List<File> buildClassPath(SharedClassLoader classLoader, String rawcp) throws IOException {
068        List<File> result = new ArrayList<>();
069        String[] cp = rawcp.split(":");
070        for (String entry : cp) {
071            File entryFile;
072            if (entry.endsWith("/.")) {
073                entryFile = new File(entry.substring(0, entry.length() - 2));
074                File[] files = entryFile.listFiles();
075                if (files != null) {
076                    for (File file : files) {
077                        result.add(file);
078                        classLoader.addURL(file.toURI().toURL());
079                    }
080                }
081            } else {
082                entryFile = new File(entry);
083                result.add(entryFile);
084                classLoader.addURL(entryFile.toURI().toURL());
085            }
086        }
087        return result;
088    }
089
090    private static class RootClassLoader extends ClassLoader {
091
092        private final Class<?> loaderClass;
093
094        private final String loaderName;
095
096        RootClassLoader(ClassLoader parent, Class<?> loaderClass) {
097            super(parent);
098            this.loaderClass = loaderClass;
099            loaderName = loaderClass.getName();
100        }
101
102        @Override
103        protected Class<?> findClass(String name) throws ClassNotFoundException {
104            if (loaderName.equals(name)) {
105                return loaderClass;
106            }
107            throw new ClassNotFoundException(name);
108        }
109
110    }
111
112}