ZipUtil.java

/*
 *
 * Copyright SHMsoft, Inc. 
 *
 * Licensed 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.freeeed.search.files;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;

public class ZipUtil {

    /**
     * Create a zip file from the given directory to zip.
     *
     * @param zipFileName
     * @param directoryToZip
     * @throws IOException
     */
    public static void createZipFile(String zipFileName, String directoryToZip) throws IOException {
        //create object of FileOutputStream
        FileOutputStream fout = new FileOutputStream(zipFileName);

        //create object of ZipOutputStream from FileOutputStream
        ZipOutputStream zout = new ZipOutputStream(fout);

        //create File object from source directory
        File fileSource = new File(directoryToZip);

        addDirectory(zout, fileSource, "");

        //close the ZipOutputStream
        zout.close();
    }

    /**
     *
     * Create a zip file containing the given files.
     *
     * @param zipFileName
     * @param files
     * @throws IOException
     */
    public static void createZipFile(String zipFileName, List<File> files) throws IOException {
        //create object of FileOutputStream
        FileOutputStream fout = new FileOutputStream(zipFileName);

        //create object of ZipOutputStream from FileOutputStream
        ZipOutputStream zout = new ZipOutputStream(fout);

        addDirectory(zout, files, "");

        //close the ZipOutputStream
        zout.close();
    }

    private static void addDirectory(ZipOutputStream zout, File fileSource, String path) throws IOException {
        File[] files = fileSource.listFiles();
        Arrays.asList(files);
        addDirectory(zout, Arrays.asList(files), path);
    }

    private static void addDirectory(ZipOutputStream zout, List<File> files, String path) throws IOException {
        for (File file : files) {
            if (file.isDirectory()) {
                addDirectory(zout, file, path + file.getName() + File.separator);
                continue;
            }
            byte[] buffer = new byte[1024];
            FileInputStream fin = new FileInputStream(file);
            zout.putNextEntry(new ZipEntry(path + file.getName()));
            int length;
            while ((length = fin.read(buffer)) > 0) {
                zout.write(buffer, 0, length);
            }
            zout.closeEntry();
            fin.close();
        }
    }

    /**
     * Unzip a given zip file to a specified output directory.
     *
     * @param zipFileName
     * @param outputDir
     * @throws IOException
     */
    public static void unzipFile(String zipFileName, String outputDir)
            throws IOException {

        ZipFile zipFile = new ZipFile(new File(zipFileName));
        @SuppressWarnings("rawtypes")
        Enumeration e = zipFile.entries();

        while (e.hasMoreElements()) {
            ZipEntry entry = (ZipEntry) e.nextElement();
            File destinationFilePath = new File(outputDir, entry.getName());

            // create directories if required.
            destinationFilePath.getParentFile().mkdirs();

            // if the entry is not a directory, extract it.
            if (!entry.isDirectory()) {            
                /*
                 * Get the InputStream for current entry of the zip file using
                 * 
                 * InputStream getInputStream(Entry entry) method.
                 */
                BufferedInputStream bis = new BufferedInputStream(
                        zipFile.getInputStream(entry));

                int b;
                byte buffer[] = new byte[1024];

                /*
                 * read the current entry from the zip file, extract it and
                 * write the extracted file.
                 */
                FileOutputStream fos = new FileOutputStream(destinationFilePath);
                BufferedOutputStream bos = new BufferedOutputStream(fos, 1024);

                while ((b = bis.read(buffer, 0, 1024)) != -1) {
                    bos.write(buffer, 0, b);
                }

                // flush the output stream and close it.
                bos.flush();
                bos.close();

                // close the input stream.
                bis.close();
            }
        }
    }
}