Java Unzip File unzip(final String zipFile, final String outputFolder, final boolean createFolder)

Description

Unzip the given ZIP file in the output folder, without the root folder part

License

LGPL

Parameter

Parameter	Description
zipFile	a parameter
outputFolder	a parameter
createFolder	a parameter

Declaration

public static void unzip(final String zipFile, final String outputFolder, final boolean createFolder)
        throws Exception 

Method Source Code

//package com.java2s;
/**/*from w  ww  . j  a v  a 2  s . c  o  m*/
 *  Copyright (C) 2008-2014  Telosys project org. ( http://www.telosys.org/ )
 *
 *  Licensed under the GNU LESSER GENERAL PUBLIC LICENSE, Version 3.0 (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.gnu.org/licenses/lgpl.html
 *
 *  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.
 */

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class Main {
    /**
     * Unzip the given ZIP file in the output folder, without the root folder part 
     * @param zipFile
     * @param outputFolder
     * @param createFolder
     */
    public static void unzip(final String zipFile, final String outputFolder, final boolean createFolder)
            throws Exception {

        log("UnZip file '" + zipFile + "'");
        log("        in '" + outputFolder + "'");

        //--- Check output directory existence
        File folder = new File(outputFolder);
        if (!folder.exists()) {
            if (createFolder) {
                // folder.mkdir();
                folder.mkdirs(); // creates all parent directories 
            } else {
                throw new Exception("UnZip error : folder '" + outputFolder + "' doesn't exist");
            }
        }

        try {

            //--- Read each entry in the zip file
            ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFile));

            ZipEntry zipEntry = zis.getNextEntry();
            while (zipEntry != null) {

                final String zipEntryName = zipEntry.getName();
                log(" . unzip entry '" + zipEntryName + "'");

                // cut the root folder ( remove "basic-templates-TT207-master" ) 
                String entryDestination = cutEntryName(zipEntryName);
                if (entryDestination.length() > 0) {
                    //--- Install this entry
                    // build the destination file name
                    File destinationFile = new File(outputFolder + File.separator + entryDestination);
                    // unzip ( file or directory )
                    log("   install : " + zipEntryName);
                    log("        in : " + destinationFile.getAbsolutePath());
                    if (zipEntry.isDirectory()) {
                        destinationFile.mkdirs(); // create directory (including parents)
                    } else {
                        unzipEntry(zis, destinationFile); // extract to file
                    }
                } else {
                    log("   root entry => do not extract");
                }

                zipEntry = zis.getNextEntry();
            }

            zis.closeEntry();
            zis.close();

            log("Done");

        } catch (IOException ex) {
            log("IOException : " + ex.getMessage());
            throw new Exception("UnZip Error (IOException)", ex);
        }
    }

    private static void log(String msg) {
        //System.out.println(msg);
    }

    public static String cutEntryName(final String entryName) {

        final int pos = getFirstSeparator(entryName);
        if (pos < 0) {
            // separator not found => nothing after
            return "";
        } else {
            // separator found => cut before
            return entryName.substring(pos + 1);
        }
    }

    /**
     * Unzip the given entry (a single file stored in the zip file)
     * @param zis entry input stream
     * @param newFile the new file to be created
     * @throws IOException
     */
    private static void unzipEntry(ZipInputStream zis, File newFile) throws IOException {

        // create non existent parent folders (to avoid FileNotFoundException) ???
        // new File(newFile.getParent()).mkdirs();

        byte[] buffer = new byte[1024];
        FileOutputStream fos = new FileOutputStream(newFile);
        int len;
        while ((len = zis.read(buffer)) > 0) {
            fos.write(buffer, 0, len);
        }
        fos.close();
    }

    private static int getFirstSeparator(final String entryName) {

        for (int i = 0; i < entryName.length(); i++) {
            char c = entryName.charAt(i);
            if (c == '/' || c == '\\') {
                return i;
            }
        }
        return -1; // Not found
    }
}

Related

1. unzip(final File zipFile, final File destDir)
2. unzip(final File zipFile, final String targetDir)
3. unzip(final InputStream is, final File outputDirectory)
4. unzip(final InputStream zipFile, final File targetFolder)
5. unZip(final String result)