将给定目录的所有文件写入指定的jar

/*

 * Created on 24-Feb-2004 at 16:35:32.

 *

 * Copyright (c) 2004-2005 Robert Virkus / Enough Software

 *

 * This file is part of J2ME Polish.

 *

 * J2ME Polish is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 * 

 * J2ME Polish 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 General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with J2ME Polish; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 * 

 * Commercial licenses are also available, please

 * refer to the accompanying LICENSE.txt or visit

 * http://www.j2mepolish.org for details.

 */

//package com.nowjava;

import java.io.*;
/**来自 
 时代Java公众号 - N o w J a  v a . c o m**/


import java.util.jar.*;

import java.util.zip.CRC32;


import java.util.zip.ZipOutputStream;


public class Main {

    /**

     * Writes all files of the given directory to the specified jar-file.

     * 

     * @param sourceDir The directory containing the "source" files.

     * @param target The jar file which should be created

     * @param compress True when the jar file should be compressed

     * @throws FileNotFoundException when a file could not be found

     * @throws IOException when a file could not be read or the jar file could not be written to.

     */

    public static void jar(File sourceDir, File target, boolean compress)

            throws FileNotFoundException, IOException {

        // create target directory if necessary: 

        if (!target.getParentFile().exists()) {/** 来 自 nowjava**/

            target.getParentFile().mkdirs();

        }

        // creates target-jar-file:

        JarOutputStream out = new JarOutputStream(new FileOutputStream(

                target));

        if (compress) {

            out.setLevel(ZipOutputStream.DEFLATED);

        } else {

            out.setLevel(ZipOutputStream.STORED);

        }

        // create a CRC32 object:

        CRC32 crc = new CRC32();

        byte[] buffer = new byte[1024 * 1024];

        // read all files from the source directory:

        File[] fileNames = sourceDir.listFiles();

        int sourceDirLength = sourceDir.getAbsolutePath().length() + 1;

        for (int i = 0; i < fileNames.length; i++) {

            File file = fileNames[i];

            addFile(file, out, crc, sourceDirLength, buffer);

        }

        out.close();

    }


    /**

     * Adds one file to the given jar file.

     * If the specified file is a directory, all included files will be added.

     * 

     * @param file The file which should be added

     * @param out The jar file to which the given jar file should be added

     * @param crc A helper class for the CRC32 calculation

     * @param sourceDirLength The number of chars which can be skipped from the file's path

     * @param buffer A buffer for reading the files.

     * @throws FileNotFoundException when the file was not found

     * @throws IOException when the file could not be read or not be added

     */

    private static void addFile(File file, JarOutputStream out, CRC32 crc,

            int sourceDirLength, byte[] buffer)

            throws FileNotFoundException, IOException {

        if (file.isDirectory()) {

            File[] fileNames = file.listFiles();

            for (int i = 0; i < fileNames.length; i++) {

                addFile(fileNames[i], out, crc, sourceDirLength, buffer);

            }

        } else {