DatabaseLauncher.java :  » Math » migen » uk » ac » lkl » migen » system » Java Open Source

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();
    }
}