chatserver.java

自己写的一个聊天的小程序 请多多指教

/*
 * Copyright (c) 2003 - 2007, Silvio Meier and Tobias Reinhard
 *
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met:
 *
 *   o Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer.
 *   o Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution.
 *   o The names of its contributors may not be used to endorse 
 *     or promote products derived from this software without 
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.sf.cscc.examples.chatsystem;


import java.awt.BorderLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

import net.sf.cscc.CommunicationEvent;
import net.sf.cscc.CommunicationEventObserver;
import net.sf.cscc.DataEvent;
import net.sf.cscc.DataEventBaseObserver;
import net.sf.cscc.DataEventReceivingObserver;
import net.sf.cscc.ServerConnectionManager;


/**
 *   This class represents the server in the chatsystem. 
 *   The Chatsystem is a small application
 *   intended to demonstrate the usage of this client/server 
 *   communication component. The server manages
 *   the connections from multiple 
 *   {@link net.sf.cscc.examples.chatsystem.ChatClient} on a specific port. It sends data
 *   (messages in the chat session) received from one client to all other 
 *   clients by calling the method
 *   {@link net.sf.cscc.ServerConnectionManager#sendBroadCastEvent(DataEvent de)}. 
 *   Receiving data or informations about the status of the connection 
 *   is done by the methods {@link #receiveEvent(DataEvent de)} and
 *   {@link #receiveEvent(CommunicationEvent ce)}.<br>
 *   
 *   The server is just an example to show the usage of the 
 *   communication component. It doesn't i.e. check
 *   if the nickname is already used by another client. Instead it 
 *   allows multiple clients to use the same
 *   nickname without any authentication
 *
 *	@author			Tobias Reinhard (TR)
 *	@copyright			Silvio Meier, Tobias Reinhard, 2003
 *	@history			2003-05-18 TR First version
 *						2003-05-20 TR Reference in comment corrected
 * 						2004-12-13 SM Some cleaning of unused things.
 * 						2006-11-28 SM Comments revised.
 *	@version			$Date: 2007/07/01 17:04:07 $, $Author: reode_orm $, $Revision: 1.1 $
 */
public class ChatServer extends JFrame implements DataEventReceivingObserver, CommunicationEventObserver {

	/**
	 *   IP adress of the server.
	 */
	private InetAddress serverAddress;

	/**
	 *   Specifies the TCP port to listen for connections.
	 */
	private int portNumber = 2700;

	/**
	 *   The server connection manager which handles the 
	 *   communication with the clients.
	 */
	private ServerConnectionManager serverConnectionManager;

	/**
	 *   TextField to show the address of the server.
	 */
	private JTextField serverBar;

	/**
	 *   TextArea to dispplay the messages of the chat session.
	 */
	private JTextArea messageArea;

	/**
	 *   TextField to show status informations about the connections.
	 */
	private JTextField statusBar;

	/**
	 *  Constructor to initialize the Server.
	 *  
	 *  @pre	true
	 *  @post	serverConnectionManager != null
	 */
	public ChatServer() {
		super("Chat server");
		setSize(400, 400);
		// Initialize a new ConnectionManager for the given port
		serverConnectionManager = new ServerConnectionManager(portNumber);
		// Register the server as observer for DataEvents and CommunicationEvents
		// Casts are necassary because the two methods have the same name
		serverConnectionManager.addObserver((CommunicationEventObserver)this);
		serverConnectionManager.addObserver((DataEventReceivingObserver)this);
		// Wait for connections from the clients
		serverConnectionManager.beginListening();

		// Get the IP address of the server
		try {
			serverAddress = InetAddress.getLocalHost();
		} catch(UnknownHostException e) {}

		initGUI();

		addWindowListener(new WindowAdapter() {
            			public void windowClosing(WindowEvent evt) {
				exit();
            		}
        	});

	}

	/**
	 *   This method initializes the gui of the client.
	 *   
	 *   @pre	true
	 *   @post	true
	 */
	private void initGUI() {
		getContentPane().setLayout(new BorderLayout());

		serverBar = new JTextField("Server running at address " + serverAddress);
  		serverBar.setEditable(false);

		messageArea = new JTextArea();
		messageArea.setEditable(false);

		statusBar = new JTextField();
		statusBar.setEditable(false);

		getContentPane().add(serverBar, BorderLayout.NORTH);
		getContentPane().add(new JScrollPane(messageArea), BorderLayout.CENTER);
		getContentPane().add(statusBar, BorderLayout.SOUTH);
	}

	/**
	 *   This interface method is called by the communication component. The implenting class has to
	 *   register at the specific object of the class
	 *   {@link net.sf.cscc.ClientConnectionManager#addObserver(DataEventBaseObserver debo)}
	 *   to get notifications about new data events in the event queue. The data is given as argument.
	 *   
	 *   @pre	de != null
	 *   @post	true
	 *   @param	de DataEvent object, encapsulating the transmitted data.
	 *   @see net.sf.cscc.DataEventObserver#receiveEvent()
	 */
	public void receiveEvent(DataEvent de) {
		// send received message to all clients (including the sender of the message)
		messageArea.append(de.getData().toString());
		serverConnectionManager.sendBroadCastEvent(de);
	}

	/**
	 *   This interface method is called by communication component class, 
	 *   every time a communication event occurred. The implenting class has 
	 *   to register at the specific object of the class 
	 *   {@link net.sf.cscc.ClientConnectionManager#addObserver(DataEventBaseObserver debo)}
	 *   to get notifications about new communication events in the event queue. 
	 *   This is done by calling the method 
	 *   {@link net.sf.cscc.ServerConnectionManager#addObserver(CommunicationEventObserver o)}
	 *   for observing the communication events of the server, respectively 
	 *   the method {@link net.sf.cscc.ClientConnectionManager#addObserver(CommunicationEventObserver o)} 
	 *   for the communication events of the client.
	 *   
	 *   @pre	ce != null
	 *   @post	true
	 *   @param ce CommunicationEvent which is delivered to the implementor of
	 *             this interface (ie. the observer).
	 */
	public void receiveEvent(CommunicationEvent ce) {
		switch(ce.getEventId()) {
			case(CommunicationEvent.CONNECTION_ESTABLISHED):
				statusBar.setText(ce.getData() + " connected to server!\n");
				break;
			case(CommunicationEvent.CONNECTION_BROKEN):
				statusBar.setText("Connection to " + ce.getData() + " broken!\n");
				break;
			case(CommunicationEvent.CONNECTION_CLOSED):
				statusBar.setText(ce.getData() + "disconnected from server!");
				break;
		}
	}

	/**
	 *   Method to terminate the application.
	 *   
	 *   @pre	true
	 *   @post	true
	 */
	public void exit() {
		serverConnectionManager.closeAllConnections();
		System.exit(0);
	}

	/**
	 *   This method starts up the client.
	 *   
	 *   @pre	true
	 *   @post	ChatClient != null
	 *   @param	args the command line arguments
	 */
	public static void main(String[] args) {
		new ChatServer().setVisible(true);
	}
}