source: main/trunk/gli/src/org/greenstone/gatherer/util/UnzipTools.java

/**
 *############################################################################
 * A component of the Greenstone Librarian Interface, part of the Greenstone
 * digital library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: David Bainbridge, NZDL Project, University of Waikato, NZ
 *
 * Copyright (C) 2005 New Zealand Digital Library Project
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *############################################################################
 */

package org.greenstone.gatherer.util;


import java.io.*;
import java.util.*;
import java.util.zip.*;


public class UnzipTools
{
    static public boolean unzipFile(String zip_file_path, String base_directory_path)
    {
    boolean success = true;
    try {
        ZipFile zip_file = new ZipFile(new File(zip_file_path), ZipFile.OPEN_READ);
        
        Enumeration e = zip_file.entries(); 
        while (e.hasMoreElements()) {
        ZipEntry zip_entry = (ZipEntry) e.nextElement();
        File zip_entry_file = new File(base_directory_path + zip_entry.getName());
        // System.err.println("    Unzipping: " + zip_entry_file.getAbsolutePath());

        // Directory case
        if (zip_entry.isDirectory()) {
            // Create named directory, if it doesn't already exist
            if (!zip_entry_file.exists() && !zip_entry_file.mkdirs()) {
            System.err.println("Error: unable to create directory " + zip_entry_file);
            success = false;
            }
        }

        // File case
        else {
            // Write out file to disk

            // Make sure its parent directory exists.
            File dir = new File(zip_entry_file.getParent());
            dir.mkdirs();

            // Don't need to unzip files called empty which were created during the zipping process
            // in order to be able to generate empty directories in a zip (see remote.ZipTools)
            if(!zip_entry_file.getName().equals("empty")) {
            // Set up input stream
            InputStream zis = zip_file.getInputStream(zip_entry); 
            BufferedInputStream bzis = new BufferedInputStream(zis); 
            DataInputStream dbzis = new DataInputStream(bzis);
            
            // Set up output stream
            FileOutputStream fzos = new FileOutputStream(zip_entry_file);
            BufferedOutputStream bfzos = new BufferedOutputStream(fzos);
            
            byte[] buf = new byte[1024];
            int len;
            while ((len = dbzis.read(buf)) >= 0) {
                bfzos.write(buf,0,len);
            }
            
            dbzis.close();
            bzis.close();
            zis.close();
            
            bfzos.close();
            fzos.close();
            }
        }
        }

        zip_file.close();
    } 
    catch (Exception exception) {
        exception.printStackTrace();
        success = false;
    }

    return success;
    }
}