/java/src/uk/ac/lkl/migen/system/DatabaseLauncher.java

package uk.ac.lkl.migen.system;



import java.awt.GridLayout;

import java.awt.event.*;

import java.net.SocketException;

import java.net.UnknownHostException;

import java.util.Enumeration;

import java.net.*;



import javax.swing.*;



import uk.ac.lkl.common.util.config.*;

import uk.ac.lkl.common.util.database.*;



/**

 * The launcher for the DB server.

 * 

 * This is to enable launching the JavaDB RDBMS without all the 

 * complexity of the MiGen server. This is only useful for 

 * data analysis purposes, and not to be used in a MiGen 

 * environment: use ServerLauncher for that.  

 * 

 * @author $Author: sergut $

 * @version $Revision: 8505 $

 * @version $Date: 2011-02-17 13:15:10 +0000 (Thu, 17 Feb 2011) $

 * 

 */

public class DatabaseLauncher {

    

    /**

     * The main frame. 

     * 

     * Changes title depending on the server's state for convenience. 

     */

    private JFrame frame;



    /**

     * The quit button.

     * 

     * Get enabled/disabled depending on the state of the server.

     */

    private JButton quitButton;



    /**

     * A button to show the command to connect to the DB. 

     * 

     * Convenient for researchers. Can be configured to be shown/hidden. 

     */

    private JButton connectMessageButton; 

    

    /**

     * The name of the file (i.e. directory) where the DB is. 

     * 

     * Is selected at startup if there is more than one. 

     */

    private static String databaseFilename = null;

    

    public DatabaseLauncher() throws ConfigurationException {

	String serverName = "localhost";

	int serverPort = MiGenConfiguration.getServerPort();

	System.out.println("Launching MiGen server on " + serverName + ":" + serverPort);

	try {

	    createServerFrame();

	    DatabaseServer databaseServer = new DatabaseServer();

	    databaseServer.start();	    

	    setServerFrameAsReady();

	} catch (DatabaseException e) {

	    errorShutdown(e, "Unspecified error", ExitStatus.UNKNOWN_ERROR);

	}

    }



    private void createServerFrame() {

	frame = new JFrame("Launching...");

	frame.setLayout(new GridLayout(1,2));

	

	quitButton = new JButton("Quit server now");

	quitButton.addActionListener(new ActionListener() {

	    public void actionPerformed(ActionEvent e) {

		shutdown(ExitStatus.NO_ERROR);

	    }});

	quitButton.setEnabled(false);

	quitButton.setToolTipText("Quit the server");

	frame.add(quitButton);

	

	if (MiGenConfiguration.isShowingConnectCommandButton()) {

	    connectMessageButton = new JButton("How to connect?");

	    connectMessageButton.addActionListener(new ActionListener() {

		public void actionPerformed(ActionEvent e) {

		    printUsefulInfo();

		}});

	    connectMessageButton.setEnabled(false);

	    connectMessageButton.setToolTipText("Print useful stuff on the console");

	    frame.add(connectMessageButton);

	}

	

	frame.addWindowListener(new WindowAdapter() {

	    @Override

	    public void windowClosing(WindowEvent e) {

		shutdown(ExitStatus.NO_ERROR);

	    }});

	frame.pack();

	frame.setVisible(true);

    }



    private void setServerFrameAsReady() {

	printUsefulInfo();

	frame.setTitle("MiGen Server");

	quitButton.setEnabled(true);

	if (connectMessageButton != null)

	    connectMessageButton.setEnabled(true);	

    }



    // Convenience

    private void printUsefulInfo()  {

	// 1. Print IP addresses of all interfaces of this machine

	try {

	    InetAddress myAddress = Inet4Address.getLocalHost();

	    System.out.println("\nCurrent host: " + myAddress.getCanonicalHostName() + ":" + myAddress.getHostAddress());

	    System.out.println("All IP addresses of " + myAddress.getHostName() + ":");

	    for (Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces(); interfaces.hasMoreElements();) {

		NetworkInterface networkInterface = interfaces.nextElement();

		for (Enumeration<InetAddress> addresses = networkInterface.getInetAddresses(); addresses.hasMoreElements();) {

		    InetAddress address = addresses.nextElement();

		    if (address instanceof Inet4Address)

			System.out.println("   * IP4: " + address.getHostAddress());

		    else

			System.out.println("   * IP6: " + address.getHostAddress());

		}

	    }	    

	} catch (UnknownHostException e) {

	    e.printStackTrace();

	} catch (SocketException e) {

	    e.printStackTrace();

	}

	System.out.println("Waiting for HTTP requests on port " + MiGenConfiguration.getServerPort());

	// 2. Print command to access DB

	System.out.println("To fix errors in DB by hand:\nconnect 'jdbc:derby://localhost:1527/" + databaseFilename + "';");

    }



    /**

     * This method exits the server cleanly (e.g. freeing the ports, etc). 

     * 

     * All exit paths should call this method instead of System.exit() to 

     * ensure that everything is in order before closing the application. 

     * 

     * @param exitStatus the exit status to be returned to the operating system.

     */

    public static void shutdown(ExitStatus exitStatus) {

	System.out.println("MiGen server halted.");

	System.exit(exitStatus.toInt());

    }



    // convenience for clarity

    private static void errorShutdown(Exception e, String msg, ExitStatus exitStatus) {

	if (e != null) 

	    e.printStackTrace();

	JOptionPane.showMessageDialog(null, msg, "Server Error", JOptionPane.ERROR_MESSAGE);

	shutdown(exitStatus);	

    }

    

    public static void main(String[] args) throws Exception {

	new DatabaseLauncher();

    }

}