source: trunk/gli/src/org/greenstone/gatherer/LocalLibraryServer.java@ 8620

/**
 *############################################################################
 * 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) 2004 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;


import java.io.*;
import java.lang.*;
import java.net.*;
import javax.swing.*;
import org.greenstone.gatherer.util.GSDLSiteConfig;
import org.greenstone.gatherer.util.Utility;


public class LocalLibraryServer
{
    static private GSDLSiteConfig gsdlsite_cfg = null;
    static private boolean running = false;


    static public void addCollection(String collection_name)
    {
    config(GSDLSiteConfig.ADD_COMMAND + collection_name);
    // This is very important -- it ensures that the above command has finished
    config("");
    }


    // Used to send messages to the local library
    // Warning: this has a lot of potential for nasty race conditions
    // The response code is returned immediately -- but this does not mean the local
    //   library action has finished!
    static private void config(String command)
    {
    try {
        String raw_url = Configuration.exec_address.toString() + command;
        URL url = new URL(raw_url);
        DebugStream.println("Action: " + raw_url);
        HttpURLConnection library_connection = (HttpURLConnection) url.openConnection();
        int response_code = library_connection.getResponseCode();
        if(HttpURLConnection.HTTP_OK <= response_code && response_code < HttpURLConnection.HTTP_MULT_CHOICE) {
        DebugStream.println("200 - Complete.");
        }
        else {
        DebugStream.println("404 - Failed.");
        }
        url = null;
    }
    catch (Exception ex) {
        DebugStream.printStackTrace(ex);
    }
    }


    static public boolean isRunning()
    {
    return running;
    }


    static public void releaseCollection(String collection_name)
    {
    config(GSDLSiteConfig.RELEASE_COMMAND + collection_name);
    // This is very important -- it ensures that the above command has finished
    config("");
    }


    static public void start(String gsdl_path, String local_library_server_file_path)
    {
    File local_library_server_file = new File(local_library_server_file_path);
    if (!local_library_server_file.exists()) {
        DebugStream.println("No local library at given file path.");

        local_library_server_file = new File(gsdl_path + Utility.SERVER_EXE);
        if (!local_library_server_file.exists()) {
        DebugStream.println("No local library at all.");
        return;
        }
    }

    // First of all we create a GSDLSiteCFG object and check if a URL is already present, in which case the server is already running.
    gsdlsite_cfg = new GSDLSiteConfig(local_library_server_file);
    String url = gsdlsite_cfg.getURL();
    // If its already running then set exec address.
    if(url != null) {
        try {
        Configuration.exec_address = new URL(url);
        }
        catch(Exception error) {
        }
    }
    // Otherwise its time to run the server in a spawned process.
    if(Configuration.exec_address == null && local_library_server_file.exists()) {
        // Configure for immediate entry. Note that this only works if the gsdlsite.cfg file exists.
        gsdlsite_cfg.set();

        // Spawn local library server process
        String local_library_server_command = local_library_server_file.getAbsolutePath() + " " + gsdlsite_cfg.getSiteConfigFilename();
        Gatherer.self.spawnApplication(local_library_server_command);

        // Now we have to wait until program has started. We do this by reloading and checking
        ///ystem.err.print("Waiting until the local library has loaded");
        try {
        gsdlsite_cfg.load();
            
        int try_again = JOptionPane.YES_OPTION;
        int attempt_count = 0;
        while(gsdlsite_cfg.getURL() == null && try_again == JOptionPane.YES_OPTION) {
            ///ystem.err.print(".");
            if(attempt_count == 60) {
            attempt_count = 0;
            try_again = JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("Server.QuitTimeOut"), Dictionary.get("General.Warning"), JOptionPane.YES_NO_OPTION);
            }
            else {
            new OneSecondWait();  // Wait one second (give or take)
            gsdlsite_cfg.load();
            attempt_count++;
            }
        }
            
        if((url = gsdlsite_cfg.getURL()) != null) {
            // Ta-da. Now the url should be available.
            Configuration.exec_address = new URL(url);
            
            // A quick test involves opening a connection to get the home page  for this collection. If this fails then we try changing the url to be localhost.
            try {
            DebugStream.println("Try connecting to server on config url: '" + Configuration.exec_address + "'");
            URLConnection connection = Configuration.exec_address.openConnection();
            connection.getContent();
            }
            catch(IOException bad_url_connection) {
            try {
                DebugStream.println("Try connecting to server on local host: '" + gsdlsite_cfg.getLocalHostURL() + "'");
                Configuration.exec_address = new URL(gsdlsite_cfg.getLocalHostURL   ());
                URLConnection connection = Configuration.exec_address.openConnection();
                connection.getContent();
            }
            catch(IOException worse_url_connection) {
                DebugStream.println("Can't connect to server on either address.");
                Configuration.exec_address = null;
            }
            }
        }
        }
        catch (Exception exception) {
        DebugStream.printStackTrace(exception);
        }
    }
    DebugStream.println("Having started server.exe, exec_address is: " + Configuration.exec_address);
    }


    static public void stop()
    {
    if (running == true && Configuration.exec_address != null) {
        // See if its already exited for some reason.
        gsdlsite_cfg.load();
        if(gsdlsite_cfg.getURL() != null) {
        // Send the command for it to exit.
        config(GSDLSiteConfig.QUIT_COMMAND);
        // Wait until it exits.
        try {
            gsdlsite_cfg.load();
            int try_again = JOptionPane.YES_OPTION;
            int attempt_count = 0;
            while(gsdlsite_cfg.getURL() != null && try_again == JOptionPane.YES_OPTION) {
            if(attempt_count == 60) {
                attempt_count = 0;
                try_again = JOptionPane.showConfirmDialog(Gatherer.g_man, Dictionary.get("Server.QuitTimeOut"), Dictionary.get("General.Warning"), JOptionPane.YES_NO_OPTION);
            }
            else {
                new OneSecondWait();  // Wait one second (give or take)
                gsdlsite_cfg.load();
                attempt_count++;
            }
            }
            //if(gsdlsite_cfg.getURL() != null) {
            //JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("Server.QuitManual"), Dictionary.get("General.Error"), JOptionPane.ERROR_MESSAGE);
            //}
        }
        catch (Exception exception) {
            DebugStream.printStackTrace(exception);
        }
        }
        // Restore the gsdlsite_cfg.
        if(gsdlsite_cfg != null) {
        gsdlsite_cfg.restore();
        }
        // If the local server is still running then our changed values will get overwritten.
        if(gsdlsite_cfg.getURL() != null) {
        JOptionPane.showMessageDialog(Gatherer.g_man, Dictionary.get("Server.QuitFailed"), Dictionary.get("General.Error"), JOptionPane.ERROR_MESSAGE);
        }
        gsdlsite_cfg = null;
    }
    }


    static public class OneSecondWait
    {
    public OneSecondWait()
    {
        try {
        wait(1000);
        }
        catch (InterruptedException exception) {
        }
    }
    }
}