org.apache.hadoop.hbase.util.RunTrigger.java Source code

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Here is the source code for org.apache.hadoop.hbase.util.RunTrigger.java

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/*
 * 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.hadoop.hbase.util;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

import org.apache.commons.io.FileUtils;
import org.apache.hadoop.fs.FileUtil;

public class RunTrigger {

    public static void unJar(File jarFile, File toDir) throws IOException {
        JarFile jar = new JarFile(jarFile);
        try {
            Enumeration entries = jar.entries();
            while (entries.hasMoreElements()) {
                JarEntry entry = (JarEntry) entries.nextElement();
                if (!entry.isDirectory()) {
                    InputStream in = jar.getInputStream(entry);
                    try {
                        File file = new File(toDir, entry.getName());
                        if (!file.getParentFile().mkdirs()) {
                            if (!file.getParentFile().isDirectory()) {
                                throw new IOException("Mkdirs failed to create " + file.getParentFile().toString());
                            }
                        }
                        OutputStream out = new FileOutputStream(file);
                        try {
                            byte[] buffer = new byte[8192];
                            int i;
                            while ((i = in.read(buffer)) != -1) {
                                out.write(buffer, 0, i);
                            }
                        } finally {
                            out.close();
                        }
                    } finally {
                        in.close();
                    }
                }
            }
        } finally {
            jar.close();
        }
    }

    /**
     * @param args
     * @throws Throwable 
     */
    public static void main(String[] args) throws Throwable {
        String usage = "RunTrigger jarFile [mainClass] args...";

        if (args.length < 1) {
            System.err.println(usage);
            System.exit(-1);
        }
        int firstArg = 0;
        String fileName = args[firstArg++];
        File file = new File(fileName);
        File tmpJarFile = new File("/tmp/hbase/triggerJar/trigger.jar");
        if (tmpJarFile.exists()) {
            tmpJarFile.delete();
        }
        FileUtils.copyFile(file, tmpJarFile);

        String mainClassName = null;
        JarFile jarFile;
        try {
            jarFile = new JarFile(fileName);
        } catch (IOException e) {
            throw new IOException("Error opening trigger jar: " + fileName).initCause(e);
        }

        Manifest manifest = jarFile.getManifest();
        if (manifest != null) {
            mainClassName = manifest.getMainAttributes().getValue("Main-Class");
        }
        jarFile.close();
        System.out.println("Manifest From Jar: " + mainClassName);

        if (mainClassName == null) {
            if (args.length < 2) {
                System.err.println(usage);
                System.exit(-1);
            }
            mainClassName = args[firstArg++];
        }
        System.out.println("Manifest class from argument: " + mainClassName);

        mainClassName = mainClassName.replace("/", ".");

        //'hbase.tmp.dir'
        File tmpDir = new File("/tmp/hbase/trigger/");

        tmpDir.mkdirs();
        if (!tmpDir.isDirectory()) {
            System.err.println("Mkdirs failed to create " + tmpDir);
            System.exit(-1);
        }
        final File workDir = File.createTempFile("trigger-unjar", "", tmpDir);
        workDir.delete();
        workDir.mkdirs();
        if (!workDir.isDirectory()) {
            System.err.println("Mkdirs failed to create " + workDir);
            System.exit(-1);
        }

        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                try {
                    FileUtil.fullyDelete(workDir);
                } catch (IOException e) {
                }
            }
        });

        unJar(file, workDir);

        ArrayList<URL> classPath = new ArrayList<URL>();
        classPath.add(new File(workDir + "/").toURL());
        classPath.add(file.toURL());
        classPath.add(new File(workDir, "classes/").toURL());
        File[] libs = new File(workDir, "lib").listFiles();
        if (libs != null) {
            for (int i = 0; i < libs.length; i++) {
                classPath.add(libs[i].toURL());
            }
        }

        ClassLoader loader = new URLClassLoader(classPath.toArray(new URL[0]));
        Thread.currentThread().setContextClassLoader(loader);
        Class<?> mainClass = Class.forName(mainClassName, true, loader);
        Method main = mainClass.getMethod("main", new Class[] { Array.newInstance(String.class, 0).getClass() });
        String[] newArgs = Arrays.asList(args).subList(firstArg, args.length).toArray(new String[0]);
        try {
            main.invoke(null, new Object[] { newArgs });
        } catch (InvocationTargetException e) {
            throw e.getTargetException();
        }
    }

}