source: main/trunk/gli/src/org/greenstone/gatherer/util/JarTools.java@ 32271

/**
 *############################################################################
 * 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: Michael Dewsnip, 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.awt.*;
import java.io.*;
import java.net.*;
import javax.swing.*;
import org.greenstone.gatherer.DebugStream;


public class JarTools
{
    static private Class root_class = null;
    static private ImageIcon ERROR_ICON = null; 


    static public void initialise(Object root_object)
    {   
    initialise(root_object.getClass());
    }
    
    static public void initialise(Class rootClass)
    {
    root_class = rootClass;
    ERROR_ICON = getImage("error.gif");
    }


    static public void extractFromJar(String filename, String dst_dir, boolean must_be_present) 
    {
    try {
        // setup input stream for slurping out file
        InputStream fis = root_class.getResourceAsStream("/"+filename);
        BufferedInputStream fbis = new BufferedInputStream(fis); 
        DataInputStream fdbis = new DataInputStream(fbis);

        // set up output stream for writing to disk
        String ofname = dst_dir + filename;
        FileOutputStream fos = new FileOutputStream(ofname);
        BufferedOutputStream bfos = new BufferedOutputStream(fos);

        byte[] buf = new byte[1024];
        int len;
        int total_bytes = 0;
        while ((len = fdbis.read(buf)) >= 0) {
        bfos.write(buf,0,len);
        total_bytes += len;
        }

        fdbis.close();
        bfos.close();
    }
    catch (Exception exception) {
        if (must_be_present) {
        exception.printStackTrace();
        }
    }
    }


    /** Method to retrieve an image icon with the given filename found in classpath or the resouces directory.
     *  @return The specified <strong>ImageIcon</strong>, or an error image replacement if no such images exists.
     */
    static public ImageIcon getImage(String filename) {
    return getImage(filename, false);
    }

    static public ImageIcon getImage(String filename, boolean wait_until_complete)
    {
    ImageIcon image = null;
    try {
        image = new ImageIcon(root_class.getResource("/images/" + filename));
    }
    catch (NullPointerException exception) {
        System.err.println("Error: Could not load image " + filename);
        DebugStream.println("Error: Could not load image " + filename);
    }

    if (image == null) {
        image = ERROR_ICON;
    }

    if (wait_until_complete) {
        int load_status;
        do {
        load_status = image.getImageLoadStatus();
        }
        while (load_status != MediaTracker.ABORTED && load_status != MediaTracker.ERRORED && load_status != MediaTracker.COMPLETE);
    }

    return image;
    }


    static public URL getResource(String resource_name)
    {
    return root_class.getResource(resource_name);
    }


    static public InputStream getResourceAsStream(String resource_name)
    {
    return root_class.getResourceAsStream(resource_name);
    }


    static public boolean isInJar(String filename) 
    {
    InputStream fis = null;
    try {
        fis = root_class.getResourceAsStream("/" + filename);
        if(fis == null) {
            System.err.println("@@@ JarTools.isInJar(): file inputstream for file /"+filename+" is still null. Not in jar file.");
            return false;
        }
    }
    catch (Exception exception) {
        exception.printStackTrace();
        return false;
    }
    finally {
        if(!SafeProcess.closeResource(fis)) {
            System.err.println("@@@ JarTools.isInJar(): Couldn't close file inputstream");
            return false;
        }
    }

    return true;
    }
}