chatclient.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.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

import net.sf.cscc.ClientConnectionManager;
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;


/**
 *  This class represents the client in a client/server-chatsystem. The Chatsystem is a small application
 *  intended to demonstrate the usage of this client/server communication component. The Client has to
 *  connect to a {@link net.sf.cscc.examples.chatsystem.ChatServer} to participate a session. The client sends data to
 *  the server by calling the method {@link net.sf.cscc.ClientConnectionManager#sendDataEvent(DataEvent de)}
 *  and receives data from the server by calls of the method {@link #receiveEvent(DataEvent de)}.
 *  The method {@link #receiveEvent(CommunicationEvent ce)} allows the client to receive informations
 *  about the status of the connection.
 *
 *	@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
 *						2006-11-28 SM Comments revised.
 *	@version			$Date: 2007/07/01 17:04:07 $, $Author: reode_orm $, $Revision: 1.1 $
 */
public class ChatClient extends JFrame implements ActionListener, DataEventReceivingObserver, CommunicationEventObserver {

	/**
	 *  Client connection manager, handles the connection to the server.
	 */
	private ClientConnectionManager clientConnectionManager;

	/**
	 *  Status of the connection (connected or not connected).
	 */
	private boolean connected = false;

	/**
	 *  TCP port of the connection.
	 */
	private int port = 2700;

	/**
	 *  Name to appear in the chat session.
	 */
	public String nickname;

	/**
	 *  TextField for DNS name or IP address of the server.
	 */
	private JTextField serverField;

	/**
	 *  Textfield for entering the name to appear in the chat session.
	 */
	private JTextField nicknameField;

	/**
	 *  Button to connect to the server.
	 */
	private JButton connectButton;

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

	/**
	 *  TextField for entering a message to send.
	 */
	private JTextField messageField;

	/**
	 *  Button to send the message.
	 */
	private JButton sendButton;

	/**
	 *  Constructor to initialize the Client.
	 *  @pre	true
	 *  @post	clientConnectionManager != null
	 */
	public ChatClient() {
		super("Chat Client");
		// Initialize a new connectionManager for the given port
		clientConnectionManager = new ClientConnectionManager(port);
		// Register the client as observer for DataEvents and CommunicationEvents
		// Casts are necassary because the two methods have the same name
		clientConnectionManager.addObserver((CommunicationEventObserver)this);
		clientConnectionManager.addObserver((DataEventReceivingObserver)this);

		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() {
		setSize(550, 450);
		getContentPane().setLayout(new BorderLayout());

		JPanel connectionPanel = new JPanel();
		connectionPanel.setLayout(new GridLayout(1, 5));

		connectionPanel.add(new JLabel(" Nickname: "));
		nicknameField = new JTextField();
		connectionPanel.add(nicknameField);
		connectionPanel.add(new JLabel(" Server: "));
		serverField = new JTextField("localhost");
		connectionPanel.add(serverField);
		connectButton = new JButton("connect");
		connectButton.addActionListener(this);
		connectionPanel.add(connectButton);

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

		JPanel messagePanel = new JPanel();

		messagePanel.setLayout(new BorderLayout());
		messagePanel.add(new JLabel(" Message: "), BorderLayout.WEST);
		messageField = new JTextField();
		messageField.addActionListener(this);
		messagePanel.add(messageField, BorderLayout.CENTER);
		sendButton = new JButton("send message");
		sendButton.addActionListener(this);
		messagePanel.add(sendButton, BorderLayout.EAST);

		getContentPane().add(connectionPanel, BorderLayout.NORTH);
		getContentPane().add(new JScrollPane(messageArea), BorderLayout.CENTER);
		getContentPane().add(messagePanel, BorderLayout.SOUTH);
	}

	/**
	 *   This method handles button pressed events, 
	 *   ie. <i>Connect/Disconnect</i> and <i>send message</i>.
	 *   @pre	event != null
	 *   @post	true
	 *   @param	event ActionEvent object describing which kind of event 
	 *          occurred in the gui.
	 */
	public void actionPerformed(ActionEvent event) {
		if(event.getSource() == connectButton && !connected) {
			nickname = nicknameField.getText();
			if(nickname.equals("")) {
				messageArea.append("Please enter a nickname!\n");
			} else {
				clientConnectionManager.open(serverField.getText());
			}
		}
		else if(event.getSource() == connectButton && connected) {
			clientConnectionManager.close();
		}
		else if((event.getSource() == sendButton || event.getSource() == messageField) && connected) {
			// Get Message, concatenate with nickname and send this String to the server
			if(!messageField.getText().equals("")) {
				String message = nickname + ": " + messageField.getText() + "\n";
				DataEvent de = new DataEvent(new Integer(1), message);
				clientConnectionManager.sendDataEvent(de);
				messageField.setText("");
			}
		}
	}

	/**
	 *   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) {
		// Show received messages in the messageArea
		messageArea.append(de.getData().toString());
	}

	/**
	 *   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):
				messageArea.append("ChatServer: Connection established!\n");
				connected = true;
				connectButton.setText("disconnect");
				break;
			case (CommunicationEvent.CONNECTION_BROKEN):
                		messageArea.append("ChatServer: Connection closed!\n");
				connected = false;
				connectButton.setText("connect");
                		break;
			case (CommunicationEvent.CONNECTION_CLOSED):
                		messageArea.append("ChatServer: Connection closed!\n");
				connected = false;
				connectButton.setText("connect");
                		break;
		}
	}

	/**
	 *   Method to terminate the application.
	 *   
	 *   @pre	true
	 *   @post	true
	 */
	public void exit() {
		clientConnectionManager.close();
		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 ChatClient().setVisible(true);
	}
}