source: gli/trunk/src/org/greenstone/gatherer/remote/RemoteGreenstoneServer.java@ 15863

/**
 *#########################################################################
 *
 * A component of the Gatherer application, 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
 *
 * 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.remote;

import java.io.*;
import java.net.*;
import java.util.*;
import java.util.zip.*;
import javax.swing.*;
import java.io.ByteArrayOutputStream;
import org.greenstone.gatherer.Configuration;
import org.greenstone.gatherer.DebugStream;
import org.greenstone.gatherer.Dictionary;
import org.greenstone.gatherer.FedoraInfo;
import org.greenstone.gatherer.GAuthenticator;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.collection.CollectionManager;
import org.greenstone.gatherer.shell.GShell;
import org.greenstone.gatherer.util.UnzipTools;
import org.greenstone.gatherer.util.Utility;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
import org.apache.commons.httpclient.methods.multipart.*;
import org.apache.commons.httpclient.params.*;
import org.apache.commons.httpclient.HttpStatus;

public class RemoteGreenstoneServer
{
    // ----------------------------------------------------------------------------------------------------
    //   PUBLIC LAYER
    // ----------------------------------------------------------------------------------------------------


    static public String deleteCollection(String collection_name)
    {
    return performAction(new RemoteGreenstoneServerDeleteCollectionAction(collection_name));
    }


    static public String deleteCollectionFile(String collection_name, File collection_file)
    {
    return performAction(new RemoteGreenstoneServerDeleteCollectionFileAction(collection_name, collection_file));
    }


    static public String downloadCollection(String collection_name)
    {
    return performAction(new RemoteGreenstoneServerDownloadCollectionAction(collection_name));
    }


    static public String downloadCollectionArchives(String collection_name)
    {
    return performAction(new RemoteGreenstoneServerDownloadCollectionArchivesAction(collection_name));
    }


    static public String downloadCollectionConfigurations()
    {
    return performAction(new RemoteGreenstoneServerDownloadCollectionConfigurationsAction());
    }


    static public String downloadCollectionFile(String collection_name, File collection_file)
    {
    return performAction(new RemoteGreenstoneServerDownloadCollectionFileAction(collection_name, collection_file));
    }
    
    // get web.xml from the server -- for a remote gli of GS3
    static public String downloadWebXMLFile()
    {
    return performAction(new RemoteGreenstoneServerDownloadWebXMLFileAction());
    }

    static public String getScriptOptions(String script_name, String script_arguments)
    {
    return performAction(new RemoteGreenstoneServerGetScriptOptionsAction(script_name, script_arguments));
    }
    
    //get all available site names from the server -- for a remote gli of GS3
    static public String getSiteNames()
    {
    return performAction(new RemoteGreenstoneServerGetSiteNamesAction());
    }

    static public String moveCollectionFile(String collection_name, File source_collection_file, File target_collection_file)
    {
    return performAction(new RemoteGreenstoneServerMoveCollectionFileAction(collection_name, source_collection_file, target_collection_file));
    }


    static public String newCollectionDirectory(String collection_name, File new_collection_directory)
    {
    return performAction(new RemoteGreenstoneServerNewCollectionDirectoryAction(collection_name, new_collection_directory));
    }


    static public String runScript(String collection_name, String script_name, String script_arguments, GShell shell)
    {
    return performAction(new RemoteGreenstoneServerRunScriptAction(collection_name, script_name, script_arguments, shell));
    }


    static public String uploadCollectionFile(String collection_name, File collection_file)
    {
    return performAction(new RemoteGreenstoneServerUploadCollectionFilesAction(collection_name, new File[] { collection_file }));
    }


    static public String uploadCollectionFiles(String collection_name, File[] collection_files)
    {
    return performAction(new RemoteGreenstoneServerUploadCollectionFilesAction(collection_name, collection_files));
    }


    static public String uploadFilesIntoCollection(String collection_name, File[] source_files, File target_collection_directory)
    {
    return performAction(new RemoteGreenstoneServerUploadFilesIntoCollectionAction(collection_name, source_files, target_collection_directory));
    }

    static public boolean exists(String collection_name, File collection_file)
    {
    String result = performAction(new RemoteGreenstoneServerExistsAction(collection_name, collection_file));
    if(result.indexOf("exists") != -1) {
        return true;
    }
    else if(result.indexOf("does not exist") != -1) {
        return false;
    }
    return false;
    }

    // ----------------------------------------------------------------------------------------------------


    static public void exit()
    {
    System.err.println("Exiting, number of jobs on queue: " + remote_greenstone_server_action_queue.size());

    // If there are still jobs on the queue we must wait for the jobs to finish
    while (remote_greenstone_server_action_queue.size() > 0) {
        synchronized (remote_greenstone_server_action_queue) {
        try {
            DebugStream.println("Waiting for queue to become empty...");
            remote_greenstone_server_action_queue.wait(500);
        }
        catch (InterruptedException exception) {}
        }
    }
    }


    // ----------------------------------------------------------------------------------------------------
    //   QUEUE LAYER
    // ----------------------------------------------------------------------------------------------------


    /** Returns null if we cannot wait for the action to finish, "" if the action failed, or the action output. */
    static private String performAction(RemoteGreenstoneServerAction remote_greenstone_server_action)
    {
    // Add the action to the queue
    remote_greenstone_server_action_queue.addAction(remote_greenstone_server_action);

    // If we're running in the GUI thread we must return immediately
    // We cannot wait for the action to complete because this will block any GUI updates
    if (SwingUtilities.isEventDispatchThread()) {
        System.err.println("WARNING: In event dispatch thread, returning immediately...");
        return null;
    }

    // Otherwise wait until the action is processed
    while (!remote_greenstone_server_action.processed) {
        synchronized (remote_greenstone_server_action) {
        try {
            DebugStream.println("Waiting for action to complete...");
            remote_greenstone_server_action.wait(500);
        }
        catch (InterruptedException exception) {}
        }
    }

    // Return "" if the action failed
    if (!remote_greenstone_server_action.processed_successfully) {
        return "";
    }
    // Otherwise return the action output
    return remote_greenstone_server_action.action_output;
    }


    static private RemoteGreenstoneServerActionQueue remote_greenstone_server_action_queue = new RemoteGreenstoneServerActionQueue();


    static private class RemoteGreenstoneServerActionQueue
    extends Thread
    {
    /** The queue of waiting jobs. */
    private ArrayList queue = null;


    public RemoteGreenstoneServerActionQueue()
    {
        if (Gatherer.isGsdlRemote) {
        queue = new ArrayList();
        start();
        }
    }


    synchronized public void addAction(RemoteGreenstoneServerAction remote_greenstone_server_action)
    {
        queue.add(remote_greenstone_server_action);
        notifyAll();
    }


    public int size()
    {
        return queue.size();
    }


    public void run()
    {
        boolean exit = false;
        while (true) {
        // If there are jobs on the queue, get the next in line and process it
        if (queue.size() > 0) {
            RemoteGreenstoneServerAction remote_greenstone_server_action = (RemoteGreenstoneServerAction) queue.get(0);

            try {
            remote_greenstone_server_action.perform();

            // No exceptions were thrown, so the action was successful
            remote_greenstone_server_action.processed_successfully = true;
            }
            catch (RemoteGreenstoneServerActionCancelledException exception) {
            remote_greenstone_server_action.processed_successfully = false;
            exit = true;
            } 
            catch(java.net.ConnectException exception) {
            if(exception.getMessage().equals("Connection refused")) {
                exit = true;
            } else {
                DebugStream.printStackTrace(exception);
            }
            JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Error", exception.getMessage()), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.ERROR_MESSAGE);
            remote_greenstone_server_action.processed_successfully = false;         
            }
            catch (Exception exception) {
            DebugStream.printStackTrace(exception);
            JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Error", exception.getMessage()), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.ERROR_MESSAGE);
            remote_greenstone_server_action.processed_successfully = false;
            }

            // We're done with this action, for better or worse
            remote_greenstone_server_action.processed = true;
            queue.remove(0);
        }

        // Otherwise the queue is empty
        else {
            progress_bar.setAction(null);

            // Wait until we are notify()ed by addAction that there is a new job on the queue
            synchronized (this) {
            try {
                wait();
            }
            catch (InterruptedException exception) { }
            }
        }
        
        // stop the gazillion annoying error messages when the connection was simply
        // refused or when the user pressed Cancel in the opening dialog, by exitting
        // cleanly in one go.
        if(exit == true) {
            Gatherer.exit();
        }
        }
    }
    }


    // ----------------------------------------------------------------------------------------------------
    //   PROGRESS BAR
    // ----------------------------------------------------------------------------------------------------


    static private RemoteGreenstoneServerProgressBar progress_bar = new RemoteGreenstoneServerProgressBar();


    static private class RemoteGreenstoneServerProgressBar
    extends JProgressBar
    {
    public RemoteGreenstoneServerProgressBar()
    {
        setBackground(Configuration.getColor("coloring.collection_tree_background", false));
        setForeground(Configuration.getColor("coloring.collection_tree_foreground", false));
        setString(Dictionary.get("FileActions.No_Activity"));
        setStringPainted(true);
    }


    public void setAction(String action)
    {
        if (action != null) {
        DebugStream.println(action);
        }

        // We cannot call this from the GUI thread otherwise the progress bar won't start
        if (SwingUtilities.isEventDispatchThread()) {
        System.err.println("ERROR: RemoteGreenstoneServerProgressBar.setAction() called from event dispatch thread!");
        return;
        }

        // Set the string on the progress bar, and start or stop it
        if (action == null) {
        setString(Dictionary.get("FileActions.No_Activity"));
        setIndeterminate(false);
        }
        else {
        setString(action);
        setIndeterminate(true);
        }
    }
    }


    static public RemoteGreenstoneServerProgressBar getProgressBar()
    {
    return progress_bar;
    }


    // ----------------------------------------------------------------------------------------------------
    //   ACTIONS
    // ----------------------------------------------------------------------------------------------------


    static private abstract class RemoteGreenstoneServerAction
    {
    public String action_output = null;
    public boolean processed = false;
    public boolean processed_successfully;

    abstract public void perform()
        throws Exception;
    }


    static private class RemoteGreenstoneServerActionCancelledException
    extends Exception
    {
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    DELETE COLLECTION
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDeleteCollectionAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;

    public RemoteGreenstoneServerDeleteCollectionAction(String collection_name)
    {
        this.collection_name = collection_name;
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Deleting collection " + collection_name + "...");

        String delete_collection_command = "cmd=delete-collection";
        delete_collection_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        action_output = sendCommandToServer(delete_collection_command, null);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    DELETE COLLECTION FILE
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDeleteCollectionFileAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File collection_file;

    public RemoteGreenstoneServerDeleteCollectionFileAction(String collection_name, File collection_file)
    {
        this.collection_name = collection_name;
        this.collection_file = collection_file;
    }

    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String collection_file_relative_path = getPathRelativeToDirectory(collection_file, collection_directory_path);
        collection_file_relative_path = collection_file_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        progress_bar.setAction("Deleting collection file " + collection_file_relative_path + "...");

        String delete_collection_file_command = "cmd=delete-collection-file";
        delete_collection_file_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        delete_collection_file_command += "&file=" + URLEncoder.encode(collection_file_relative_path, "UTF-8");
        action_output = sendCommandToServer(delete_collection_file_command, null);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    DOWNLOAD COLLECTION
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDownloadCollectionAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;

    public RemoteGreenstoneServerDownloadCollectionAction(String collection_name)
    {
        this.collection_name = collection_name;
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Downloading remote collection " + collection_name + "...");

        String download_collection_command = "cmd=download-collection";
        download_collection_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        String zip_file_path = Gatherer.getCollectDirectoryPath() + collection_name + ".zip";
        action_output = downloadFile(download_collection_command, zip_file_path);

        // Delete the existing (local) collection directory
        Utility.delete(new File(CollectionManager.getCollectionDirectoryPath(collection_name)));

        // Unzip the collection just downloaded
        UnzipTools.unzipFile(zip_file_path, Gatherer.getCollectDirectoryPath());
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    DOWNLOAD COLLECTION ARCHIVES
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDownloadCollectionArchivesAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;

    public RemoteGreenstoneServerDownloadCollectionArchivesAction(String collection_name)
    {
        this.collection_name = collection_name;
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Downloading collection archives for " + collection_name + "...");

        String download_collection_archives_command = "cmd=download-collection-archives";
        download_collection_archives_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        String zip_file_path = Gatherer.getCollectDirectoryPath() + collection_name + "-archives.zip";
        action_output = downloadFile(download_collection_archives_command, zip_file_path);

        // Delete the existing (local) collection archives
        Utility.delete(new File(CollectionManager.getLoadedCollectionArchivesDirectoryPath()));

        // Unzip the collection archives just downloaded
        UnzipTools.unzipFile(zip_file_path, Gatherer.getCollectDirectoryPath());
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    DOWNLOAD COLLECTION CONFIGURATIONS
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDownloadCollectionConfigurationsAction
    extends RemoteGreenstoneServerAction
    {
    public RemoteGreenstoneServerDownloadCollectionConfigurationsAction()
    {
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Downloading collection configurations...");

        // Delete the existing (local) collect directory
        Utility.delete(new File(Gatherer.getCollectDirectoryPath()));
        new File(Gatherer.getCollectDirectoryPath()).mkdirs();

        String download_collection_configurations_command = "cmd=download-collection-configurations";
        String zip_file_path = Gatherer.getCollectDirectoryPath() + "collections.zip";
        action_output = downloadFile(download_collection_configurations_command, zip_file_path);

        // Unzip the collection configurations just downloaded
        UnzipTools.unzipFile(zip_file_path, Gatherer.getCollectDirectoryPath());
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    CHECKING IF A FILE/FOLDER EXISTS ON SERVER SIDE
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerExistsAction 
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File collection_file;
    
    public RemoteGreenstoneServerExistsAction(String collection_name, File collection_file)
    {
        this.collection_name = collection_name;
        this.collection_file = collection_file;
    }
    
    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String collection_file_relative_path = getPathRelativeToDirectory(collection_file, collection_directory_path);
        collection_file_relative_path = collection_file_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        File file = new File(collection_directory_path, collection_file_relative_path);

        String file_exists_command = "cmd=file-exists";
        file_exists_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        file_exists_command += "&file=" + URLEncoder.encode(collection_file_relative_path, "UTF-8");
        // returns either "File <filename> exists" or "File <filename> does not exist"
        // for the file/folder collection_file
        action_output = sendCommandToServer(file_exists_command, null);
    }   
    }
    

    /**
     * --------------------------------------------------------------------------------------------
     *    DOWNLOAD COLLECTION FILE
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDownloadCollectionFileAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File collection_file;

    public RemoteGreenstoneServerDownloadCollectionFileAction(String collection_name, File collection_file)
    {
        this.collection_name = collection_name;
        this.collection_file = collection_file;
    }

    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String collection_file_relative_path = getPathRelativeToDirectory(collection_file, collection_directory_path);
        collection_file_relative_path = collection_file_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        progress_bar.setAction("Downloading collection file " + collection_file_relative_path + "...");

        String download_collection_file_command = "cmd=download-collection-file";
        download_collection_file_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        download_collection_file_command += "&file=" + URLEncoder.encode(collection_file_relative_path, "UTF-8");
        String zip_file_name = collection_name + "-" + collection_file.getName() + ".zip";
        String zip_file_path = collection_directory_path + zip_file_name;
        action_output = downloadFile(download_collection_file_command, zip_file_path);

        // Unzip the collection file just downloaded
        UnzipTools.unzipFile(zip_file_path, collection_directory_path);
    }
    }

    /**
     * --------------------------------------------------------------------------------------------
     *    DOWNLOAD web.xml FILE --for a remote GS3
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerDownloadWebXMLFileAction
    extends RemoteGreenstoneServerAction
    {
    public RemoteGreenstoneServerDownloadWebXMLFileAction()
    {}

    public void perform()
        throws Exception
    {
        String web_xml_directory_path=(Configuration.gli_user_directory_path);
        String download_web_xml_file_command = "cmd=download-web-xml-file";
        download_web_xml_file_command += "&file=" + URLEncoder.encode("web.xml", "UTF-8");
        String zip_file_name = "web-xml.zip";
        String zip_file_path = web_xml_directory_path + zip_file_name;
        action_output = downloadFile(download_web_xml_file_command, zip_file_path);

        // Unzip the web.xml file just downloaded
        UnzipTools.unzipFile(zip_file_path,web_xml_directory_path);
    }
    }

    /**
     * --------------------------------------------------------------------------------------------
     *    GET SCRIPT OPTIONS
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerGetScriptOptionsAction
    extends RemoteGreenstoneServerAction
    {
    private String script_name;
    private String script_arguments;

    public RemoteGreenstoneServerGetScriptOptionsAction(String script_name, String script_arguments)
    {
        this.script_name = script_name;
        this.script_arguments = script_arguments;
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Getting options for " + script_name + "...");

        String get_script_options_command = "cmd=get-script-options";
        get_script_options_command += "&script=" + script_name;
        get_script_options_command += "&xml=";
        get_script_options_command += "&language=" + Configuration.getLanguage();
        get_script_options_command += script_arguments;
        action_output = sendCommandToServer(get_script_options_command, null);
    }
    }

    /**
     * --------------------------------------------------------------------------------------------
     *    GET ALL NAMES OF SITES // for a remote GS3 
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerGetSiteNamesAction
    extends RemoteGreenstoneServerAction
    {
    public RemoteGreenstoneServerGetSiteNamesAction()
    {}

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Getting names of sites ...");

        String get_script_options_command = "cmd=get-site-names";
        action_output = sendCommandToServer(get_script_options_command, null);
    }
    }

    /**
     * --------------------------------------------------------------------------------------------
     *    MOVE COLLECTION FILE
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerMoveCollectionFileAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File source_collection_file;
    private File target_collection_file;

    public RemoteGreenstoneServerMoveCollectionFileAction(String collection_name, File source_collection_file, File target_collection_file)
    {
        this.collection_name = collection_name;
        this.source_collection_file = source_collection_file;
        this.target_collection_file = target_collection_file;
    }

    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String source_collection_file_relative_path = getPathRelativeToDirectory(source_collection_file, collection_directory_path);
        source_collection_file_relative_path = source_collection_file_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        String target_collection_file_relative_path = getPathRelativeToDirectory(target_collection_file, collection_directory_path);
        target_collection_file_relative_path = target_collection_file_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        progress_bar.setAction("Moving file " + source_collection_file_relative_path + " -> " + target_collection_file_relative_path + "...");

        String move_collection_file_command = "cmd=move-collection-file";
        move_collection_file_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        move_collection_file_command += "&source=" + URLEncoder.encode(source_collection_file_relative_path, "UTF-8");
        move_collection_file_command += "&target=" + URLEncoder.encode(target_collection_file_relative_path, "UTF-8");
        action_output = sendCommandToServer(move_collection_file_command, null);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    NEW COLLECTION DIRECTORY
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerNewCollectionDirectoryAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File new_collection_directory;

    public RemoteGreenstoneServerNewCollectionDirectoryAction(String collection_name, File new_collection_directory)
    {
        this.collection_name = collection_name;
        this.new_collection_directory = new_collection_directory;
    }

    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String new_collection_directory_relative_path = getPathRelativeToDirectory(new_collection_directory, collection_directory_path);
        new_collection_directory_relative_path = new_collection_directory_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        progress_bar.setAction("Creating new directory " + new_collection_directory_relative_path + "...");

        String new_collection_directory_command = "cmd=new-collection-directory";
        new_collection_directory_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        new_collection_directory_command += "&directory=" + URLEncoder.encode(new_collection_directory_relative_path, "UTF-8");
        action_output = sendCommandToServer(new_collection_directory_command, null);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    RUN SCRIPT
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerRunScriptAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private String script_name;
    private String script_arguments;
    private GShell shell;

    public RemoteGreenstoneServerRunScriptAction(String collection_name, String script_name, String script_arguments, GShell shell)
    {
        this.collection_name = collection_name;
        this.script_name = script_name;
        this.script_arguments = script_arguments;
        this.shell = shell;
    }

    public void perform()
        throws Exception
    {
        progress_bar.setAction("Running " + script_name + "...");

        String run_script_command = "cmd=run-script";
        run_script_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        run_script_command += "&script=" + script_name;
        run_script_command += "&language=" + Configuration.getLanguage();
        run_script_command += script_arguments;
        action_output = sendCommandToServer(run_script_command, shell);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    UPLOAD COLLECTION FILE
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerUploadCollectionFilesAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File[] collection_files;


    public RemoteGreenstoneServerUploadCollectionFilesAction(String collection_name, File[] collection_files)
    {
        this.collection_name = collection_name;
        this.collection_files = collection_files;
    }


    public void perform()
        throws Exception
    {
        progress_bar.setAction("Uploading collection files...");

        // Determine the file paths relative to the collection directory
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String[] collection_file_relative_paths = new String[collection_files.length];
        for (int i = 0; i < collection_files.length; i++) {
        collection_file_relative_paths[i] = getPathRelativeToDirectory(collection_files[i], collection_directory_path);
        }

        // Zip up the files to send to the server
        String zip_file_name = collection_name + "-" + System.currentTimeMillis() + ".zip";
        String zip_file_path = collection_directory_path + zip_file_name;
        ZipTools.zipFiles(zip_file_path, collection_directory_path, collection_file_relative_paths);

        // Upload the zip file
        String upload_collection_file_command = "cmd=upload-collection-file";
        upload_collection_file_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        upload_collection_file_command += "&file=" + URLEncoder.encode(zip_file_name, "UTF-8");
        upload_collection_file_command += "&directory=";
        upload_collection_file_command += "&zip=true";
        action_output = uploadFile(upload_collection_file_command, zip_file_path);
    }
    }


    /**
     * --------------------------------------------------------------------------------------------
     *    UPLOAD FILES INTO COLLECTION
     * --------------------------------------------------------------------------------------------
     */
    static private class RemoteGreenstoneServerUploadFilesIntoCollectionAction
    extends RemoteGreenstoneServerAction
    {
    private String collection_name;
    private File[] source_files;
    private File target_collection_directory;


    public RemoteGreenstoneServerUploadFilesIntoCollectionAction(String collection_name, File[] source_files, File target_collection_directory)
    {
        this.collection_name = collection_name;
        this.source_files = source_files;
        this.target_collection_directory = target_collection_directory;
    }


    public void perform()
        throws Exception
    {
        String collection_directory_path = CollectionManager.getCollectionDirectoryPath(collection_name);
        String target_collection_directory_relative_path = getPathRelativeToDirectory(target_collection_directory, collection_directory_path);
        target_collection_directory_relative_path = target_collection_directory_relative_path.replaceAll((Utility.isWindows() ? "\\\\" : "\\/"), "|");
        progress_bar.setAction("Uploading files into collection...");

        String zip_file_name = collection_name + "-" + System.currentTimeMillis() + ".zip";
        String zip_file_path = Gatherer.getCollectDirectoryPath() + zip_file_name;
        DebugStream.println("Zip file path: " + zip_file_path);

        String base_directory_path = source_files[0].getParentFile().getAbsolutePath();
        DebugStream.println("Base directory path: " + base_directory_path);
        String[] source_file_relative_paths = new String[source_files.length];
        for (int i = 0; i < source_files.length; i++) {
        DebugStream.println("Source file path: " + source_files[i]);
        source_file_relative_paths[i] = getPathRelativeToDirectory(source_files[i], base_directory_path);
        }

        ZipTools.zipFiles(zip_file_path, base_directory_path, source_file_relative_paths);

        String upload_collection_file_command = "cmd=upload-collection-file";
        upload_collection_file_command += "&c=" + URLEncoder.encode(collection_name, "UTF-8");
        upload_collection_file_command += "&file=" + URLEncoder.encode(zip_file_name, "UTF-8");
        upload_collection_file_command += "&directory=" + URLEncoder.encode(target_collection_directory_relative_path, "UTF-8");
        upload_collection_file_command += "&zip=true";
        action_output = uploadFile(upload_collection_file_command, zip_file_path);
    }
    }


    // ----------------------------------------------------------------------------------------------------
    //   AUTHENTICATION LAYER
    // ----------------------------------------------------------------------------------------------------


    static private PasswordAuthentication remote_greenstone_server_authentication = null;
    // static private PasswordAuthentication remote_greenstone_server_authentication = new PasswordAuthentication(System.getProperty("user.name"), new char[] { });

    static public void set_remote_greenstone_server_authentication_to_null(){
    remote_greenstone_server_authentication = null;
    }

    static private class RemoteGreenstoneServerAuthenticateTask
    extends Thread
    {
    public void run()
    {

        if (Configuration.fedora_info.isActive()) {

        FedoraInfo fedora_info = Configuration.fedora_info;
        
        String username = fedora_info.getUsername();
        String password = fedora_info.getPassword();

        //remote_greenstone_server_authentication.setUsername(fedora_info.getUsername());
        //remote_greenstone_server_authentication.setPassword(fedora_info.getPassword());

        remote_greenstone_server_authentication = new RemoteGreenstoneServerAuthenticator().getAuthentication(username,password);
        

        }
        else {
        remote_greenstone_server_authentication = new RemoteGreenstoneServerAuthenticator().getAuthentication();

        }
    }


    static private class RemoteGreenstoneServerAuthenticator
        extends GAuthenticator
    {
        public PasswordAuthentication getAuthentication(String username, String password)
        {
        return getPasswordAuthentication(username,password);
        }

        public PasswordAuthentication getAuthentication()
        {
        return getPasswordAuthentication();
        }

        protected String getMessageString()
        {
        if (Gatherer.GS3){
            return (Dictionary.get("RemoteGreenstoneServer.Authentication_Message_gs3") + " " + Configuration.site_name);
        }
        return Dictionary.get("RemoteGreenstoneServer.Authentication_Message");
        }
    }
    }


    static private void authenticateUser()
    throws RemoteGreenstoneServerActionCancelledException
    {
    // If we don't have any authentication information then ask for it now
    if (remote_greenstone_server_authentication == null) {
        try {
        // We have to do this on the GUI thread
        SwingUtilities.invokeAndWait(new RemoteGreenstoneServerAuthenticateTask());
        }
        catch (Exception exception) {
        DebugStream.printStackTrace(exception);
        }

        // If it is still null then the user has cancelled the authentication, so the action is cancelled
        if (remote_greenstone_server_authentication == null) {
        throw new RemoteGreenstoneServerActionCancelledException();
        }
    }
    }


    static public String getUsername()
    {
    if (remote_greenstone_server_authentication != null) {
        return remote_greenstone_server_authentication.getUserName();
    }

    return null;
    }


    // ----------------------------------------------------------------------------------------------------
    //   REQUEST LAYER
    // ----------------------------------------------------------------------------------------------------


    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String downloadFile(String gliserver_args, String file_path)
    throws Exception
    {
    while (true) {
        // Check that Configuration.gliserver_url is set
        if (Configuration.gliserver_url == null) {
        throw new Exception("Empty gliserver URL: please set this in Preferences before continuing.");
        }

        // Ask for authentication information (if necessary), then perform the action
        authenticateUser();
        String gliserver_url_string = Configuration.gliserver_url.toString();
        String command_output = downloadFileInternal(gliserver_url_string, gliserver_args, file_path);

        // Check the first line to see if authentication has failed; if so, go around the loop again
        if (command_output.startsWith("ERROR: Authentication failed:")) {
        JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Error", command_output.substring("ERROR: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.ERROR_MESSAGE);
        remote_greenstone_server_authentication = null;
        continue;
        }
        // Check if the collection is locked by someone else; if so, see if the user wants to steal the lock
        else if (command_output.startsWith("ERROR: Collection is locked by: ")) {
        if (JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Steal_Lock_Message", command_output.substring("ERROR: Collection is locked by: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.YES_NO_OPTION) == JOptionPane.NO_OPTION) {
            // The user has decided to cancel the action
            throw new RemoteGreenstoneServerActionCancelledException();
        }

        // The user has decided to steal the lock... rerun the command with "&steal_lock="
        gliserver_args += "&steal_lock=";
        continue;
        }
        // Handle other types of errors by throwing an exception
        else if (command_output.startsWith("ERROR: ")) {
        throw new Exception(command_output.substring("ERROR: ".length()));
        }

        // There were no exceptions thrown so the action must have succeeded
        return command_output;
    }
    }


    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String sendCommandToServer(String gliserver_args, GShell shell)
    throws Exception
    {
    while (true) {
        // Check that Configuration.gliserver_url is set
        if (Configuration.gliserver_url == null) {
        throw new Exception("Empty gliserver URL: please set this in Preferences before continuing.");
        }

        // Ask for authentication information (if necessary), then perform the action
        authenticateUser();
        String gliserver_url_string = Configuration.gliserver_url.toString();
        String command_output = sendCommandToServerInternal(gliserver_url_string, gliserver_args, shell);
        // System.err.println("Command output: " + command_output);

        // Check the first line to see if authentication has failed; if so, go around the loop again
        if (command_output.startsWith("ERROR: Authentication failed:")) {
        JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Error", command_output.substring("ERROR: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.ERROR_MESSAGE);
        remote_greenstone_server_authentication = null;
        continue;
        }
        // Check if the collection is locked by someone else; if so, see if the user wants to steal the lock
        else if (command_output.startsWith("ERROR: Collection is locked by: ")) {
        if (JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Steal_Lock_Message", command_output.substring("ERROR: Collection is locked by: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.YES_NO_OPTION) == JOptionPane.NO_OPTION) {
            // The user has decided to cancel the action
            throw new RemoteGreenstoneServerActionCancelledException();
        }

        // The user has decided to steal the lock... rerun the command with "&steal_lock="
        gliserver_args += "&steal_lock=";
        continue;
        }
        // Handle other types of errors by throwing an exception
        else if (command_output.startsWith("ERROR: ")) { 
        throw new Exception(command_output.substring("ERROR: ".length()));
        } else if (command_output.indexOf("ERROR: ") != -1) { // check if ERROR occurs anywhere else in the output
        throw new Exception(command_output);
        }

        // There were no exceptions thrown so the action must have succeeded
        return command_output;
    }
    }


    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String uploadFile(String gliserver_args, String file_path)
    throws Exception
    {
    while (true) {
        // Check that Configuration.gliserver_url is set
        if (Configuration.gliserver_url == null) {
        throw new Exception("Empty gliserver URL: please set this in Preferences before continuing.");
        }

        // Ask for authentication information (if necessary), then perform the action
        authenticateUser();
        String gliserver_url_string = Configuration.gliserver_url.toString();
        String command_output = uploadFileInternal(gliserver_url_string, gliserver_args, file_path);
        // System.err.println("Command output: " + command_output);

        // Check the first line to see if authentication has failed; if so, go around the loop again
        if (command_output.startsWith("ERROR: Authentication failed:")) {
        JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Error", command_output.substring("ERROR: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.ERROR_MESSAGE);
        remote_greenstone_server_authentication = null;
        continue;
        }
        // Check if the collection is locked by someone else; if so, see if the user wants to steal the lock
        else if (command_output.startsWith("ERROR: Collection is locked by: ")) {
        if (JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("RemoteGreenstoneServer.Steal_Lock_Message", command_output.substring("ERROR: Collection is locked by: ".length())), Dictionary.get("RemoteGreenstoneServer.Error_Title"), JOptionPane.YES_NO_OPTION) == JOptionPane.NO_OPTION) {
            // The user has decided to cancel the action
            throw new RemoteGreenstoneServerActionCancelledException();
        }

        // The user has decided to steal the lock... rerun the command with "&steal_lock="
        gliserver_args += "&steal_lock=";
        continue;
        }
        // Handle other types of errors by throwing an exception
        else if (command_output.startsWith("ERROR: ")) {
        throw new Exception(command_output.substring("ERROR: ".length()));
        }

        // There were no exceptions thrown so the action must have succeeded
        return command_output;
    }
    }


    // ----------------------------------------------------------------------------------------------------
    //   NETWORK LAYER
    // ----------------------------------------------------------------------------------------------------


    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String downloadFileInternal(String download_cgi, String cgi_args, String file_path)
    throws Exception
    {
    DebugStream.println("gliserver URL: " + download_cgi);
    System.err.println("gliserver args: " + cgi_args);

    // Add username and password, and a timestamp
    cgi_args += "&un=" + remote_greenstone_server_authentication.getUserName();
    cgi_args += "&pw=" + new String(remote_greenstone_server_authentication.getPassword());
    cgi_args += "&ts=" + System.currentTimeMillis();
    if (Gatherer.GS3){
        cgi_args += "&site=" + Configuration.site_name;
    }

    URL download_url = new URL(download_cgi);
    URLConnection dl_connection = download_url.openConnection();
    dl_connection.setDoOutput(true);
    OutputStream dl_os = dl_connection.getOutputStream();

    PrintWriter dl_out = new PrintWriter(dl_os);
    dl_out.println(cgi_args);
    dl_out.close();

    // Download result from running cgi script
    InputStream dl_is = dl_connection.getInputStream();
    BufferedInputStream dl_bis = new BufferedInputStream(dl_is);
    DataInputStream dl_dbis = new DataInputStream(dl_bis);

    String first_line = "";
    byte[] buf = new byte[1024];
    int len = dl_dbis.read(buf);
    if (len >= 0) {
        String first_chunk = new String(buf, 0, len);
        // first_line = first_chunk.substring(0, ((first_chunk.indexOf("\n") != -1) ? first_chunk.indexOf("\n") : len));
        first_line = first_chunk.substring(0, ((first_chunk.indexOf("\n") != -1) ? first_chunk.indexOf("\n") : ((first_chunk.length()<len) ? first_chunk.length():len)));
        // Save the data to file
        FileOutputStream zip_fos = new FileOutputStream(file_path);
        BufferedOutputStream zip_bfos = new BufferedOutputStream(zip_fos);

        while (len >= 0) {
        zip_bfos.write(buf, 0, len);
        len = dl_dbis.read(buf);
        }

        zip_bfos.close();
        zip_fos.close();
    }

    dl_dbis.close();
    dl_bis.close();
    dl_is.close();
    return first_line;
    }


    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String sendCommandToServerInternal(String gliserver_url_string, String cgi_args, GShell shell)
    throws Exception
    {
    DebugStream.println("gliserver URL: " + gliserver_url_string);
    System.err.println("gliserver args: " + cgi_args);

    // Add username and password, and a timestamp
    cgi_args += "&un=" + remote_greenstone_server_authentication.getUserName();
        cgi_args += "&pw=" + new String(remote_greenstone_server_authentication.getPassword());
    cgi_args += "&ts=" + System.currentTimeMillis();
    if (Gatherer.GS3){
        cgi_args += "&site=" + Configuration.site_name;
    }

    URL gliserver_url = new URL(gliserver_url_string + "?" + cgi_args);
    URLConnection gliserver_connection = gliserver_url.openConnection();

    // Read the output of the command from the server, and return it
    StringBuffer command_output_buffer = new StringBuffer(2048);
    InputStream gliserver_is = gliserver_connection.getInputStream();
    BufferedReader gliserver_in = new BufferedReader(new InputStreamReader(gliserver_is, "UTF-8"));
    String gliserver_output_line = gliserver_in.readLine();
    while (gliserver_output_line != null) {
        if (shell != null) {
        shell.fireMessage(gliserver_output_line);
        if (shell.hasSignalledStop()) {
            throw new RemoteGreenstoneServerActionCancelledException();
        }
        }
        command_output_buffer.append(gliserver_output_line + "\n");
        gliserver_output_line = gliserver_in.readLine();
    }
    gliserver_in.close();

    return command_output_buffer.toString();
    }

           
    /** Returns the command output if the action completed, throws some kind of exception otherwise. */
    static private String uploadFileInternal(String upload_cgi, String cgi_args, String file_path)
    throws Exception
    {
    //For a remote GS3
    //GS3 is running on Tomcat, and Tomcat requires a connection timeout to be set up at the client
    //side while uploading files. As HttpURLConection couldn't set the connection timeout, HttpClient.jar 
    //from Jakarta is applied to solve this problem only for uploading files. 
    if (Gatherer.GS3){
        System.err.println("gliserver URL: " + upload_cgi);
        System.err.println("gliserver args: " + cgi_args);

    // Setup the POST method
    PostMethod httppost = new PostMethod(upload_cgi+"?"+cgi_args);

    //read the zip file into a byte array
    InputStream in = new FileInputStream (file_path);
    File f = new File (file_path); // in order to get the length of the bytes array
    ByteArrayOutputStream out = new ByteArrayOutputStream ((int)f.length());
    int r = 0; // amount read
    byte[] buf = new byte[1024];
    while((r = in.read(buf, 0, buf.length)) != -1) {
        out.write(buf, 0, r);
    }
    in.close();
    byte[] result = out.toByteArray();

    // construct the multipartrequest form
    PartSource partSource = new ByteArrayPartSource("zipFile", result);
        FilePart filePart = new FilePart("uploaded_file", partSource);

    String[] cgi_array=cgi_args.split("&");// get parameter-value paires from cgi_args string
    Part[] parts=new Part[cgi_array.length+5];
    parts[0]=filePart;
    parts[1]= new StringPart("un", remote_greenstone_server_authentication.getUserName());
    parts[2]= new StringPart("pw", new String(remote_greenstone_server_authentication.getPassword()));
    parts[3]= new StringPart("ts", String.valueOf(System.currentTimeMillis()));
    parts[4]= new StringPart("site", Configuration.site_name);
    // find all parameters of cgi-agrs and add them into Part[]
    for (int i=0; i<cgi_array.length;i++){
        parts[5+i]=new StringPart(cgi_array[i].substring(0,cgi_array[i].indexOf("=")),cgi_array[i].substring(cgi_array[i].indexOf("=")+1,cgi_array[i].length()));
    }
    // set MutilartRequestEntity on the POST method
        httppost.setRequestEntity(new MultipartRequestEntity(parts, httppost.getParams()));
    //set up the HttpClient connection
    HttpClient client=new HttpClient(); 
        client.getParams().setBooleanParameter(HttpMethodParams.USE_EXPECT_CONTINUE, false);
    client.getParams().setConnectionManagerTimeout(200000); //set the connection timeout
    // get the output of the command from the server
    client.executeMethod(httppost);
    String command_output = ""; 
    try{
        client.executeMethod(httppost);
        if (httppost.getStatusCode() == HttpStatus.SC_OK) {
        command_output = httppost.getStatusLine().toString();
        } else {
        command_output = httppost.getStatusLine().toString();
        System.out.println("Unexpected failure: " + httppost.getStatusLine().toString());
        }
    }catch(IOException e){
        e.printStackTrace();
    }finally{
        httppost.releaseConnection();
    }
    return command_output;
    }

    //For a remote GS2
    System.err.println("gliserver URL: " + upload_cgi);
    System.err.println("gliserver args: " + cgi_args);
    // Add username and password, and a timestamp
    cgi_args += "&un=" + remote_greenstone_server_authentication.getUserName();
    cgi_args += "&pw=" + new String(remote_greenstone_server_authentication.getPassword());
    cgi_args += "&ts=" + System.currentTimeMillis();

    // Open a HTTP connection to the URL
    URL url = new URL(upload_cgi);
    HttpURLConnection gliserver_connection = (HttpURLConnection) url.openConnection();

    gliserver_connection.setDoInput(true);         // Allow Inputs
    gliserver_connection.setDoOutput(true);        // Allow Outputs
    gliserver_connection.setUseCaches(false);      // Don't use a cached copy.

    gliserver_connection.setRequestProperty("Connection", "Keep-Alive");        

    // Send zip file to server
    File file = new File(file_path);
    FileInputStream fileInputStream = new FileInputStream(file);

    // Add file size argument, because IIS 6 needs a lot of help
    int file_size = fileInputStream.available();
    cgi_args += "&fs=" + file_size;

    DataOutputStream dos = new DataOutputStream(gliserver_connection.getOutputStream());
    dos.writeBytes(cgi_args + "\n");

    // create a buffer of maximum size
    final int maxBufferSize = 1024;
    int bytesAvailable = file_size;
    int bufferSize = Math.min(bytesAvailable, maxBufferSize);
    byte[] buffer = new byte[bufferSize];

    // read file and write it into form...
    // !! This uses a lot of memory when the file being uploaded is big -- Java seems to need to keep
    //   the entire file in the DataOutputStream? (Use Runtime.getRuntime().totalMemory() to see)
    int bytesRead = fileInputStream.read(buffer, 0, bufferSize);
    while (bytesRead > 0) {
        dos.write(buffer, 0, bytesRead);
        bytesAvailable = fileInputStream.available();
        bufferSize = Math.min(bytesAvailable, maxBufferSize);
        bytesRead = fileInputStream.read(buffer, 0, bufferSize);
    }

    // close streams
    fileInputStream.close();
    dos.flush();
    dos.close();

    // Read the output of the command from the server, and return it
    String command_output = "";
    InputStream gliserver_is = gliserver_connection.getInputStream();
    BufferedReader gliserver_in = new BufferedReader(new InputStreamReader(gliserver_is, "UTF-8"));
    String gliserver_output_line = gliserver_in.readLine();
    while (gliserver_output_line != null) {
        command_output += gliserver_output_line + "\n";
        gliserver_output_line = gliserver_in.readLine();
    }
    gliserver_in.close();

    return command_output;
    }


    // ----------------------------------------------------------------------------------------------------
    //   UTILITIES
    // ----------------------------------------------------------------------------------------------------


    static public String getPathRelativeToDirectory(File file, String directory_path)
    {
    String file_path = file.getAbsolutePath();
    if (!file_path.startsWith(directory_path)) {
        System.err.println("ERROR: File path " + file_path + " is not a child of " + directory_path);
        return file_path;
    }

    String relative_file_path = file_path.substring(directory_path.length());
    if (relative_file_path.startsWith(File.separator)) {
        relative_file_path = relative_file_path.substring(File.separator.length());
    }
    return relative_file_path;
    }
}