简单聊天室

先起服务
import java.io.*;
import java.net.*;
import java.util.*;
import java.applet.*;
public class ChatServer implements Runnable {
	public final static int DEFAULT_PORT = 2000;
	public final static int DEFAULT_MAX_BACKLOG = 5;
	public final static int DEFAULT_MAX_CONNECTIONS = 20;
	public final static String DEFAULT_HOST_FILE = "hosts.txt";
	public final static String DEFAULT_SOUND_FILE = "file:gong.au";
	public final static String MAGIC = "Yippy Skippy";
	private String magic = MAGIC;
	private int port = DEFAULT_PORT;
	private int backlog = DEFAULT_MAX_BACKLOG;
	private int numConnections = 0;
	private int maxConnections = DEFAULT_MAX_CONNECTIONS;
	private String hostfile = DEFAULT_HOST_FILE;
	private String soundfile = DEFAULT_SOUND_FILE;
	private Vector connections = null;
	private AudioClip connectSound = null;
	private Hashtable hostInfo = new Hashtable(15);
	public static void main(String[] args) {
		ChatServer cs = new ChatServer();
		cs.go();
	}
	public void go() {
		String portString = System.getProperty("port");
		if (portString != null)
		port = Integer.parseInt(portString);
		String backlogString = System.getProperty("backlog");
		if (backlogString != null)
	    backlog = Integer.parseInt(backlogString);
		String hostFileString = System.getProperty("hostfile");
		if (hostFileString != null)
		hostfile = hostFileString;
		String soundFileString = System.getProperty("soundfile");
		if (soundFileString != null)
		soundfile = soundFileString;
		String magicString = System.getProperty("magic");
		if (magicString != null)
		magic = magicString;
		String connections = System.getProperty("connections");
		if (connections != null)
		maxConnections = Integer.parseInt(connections);
		this.connections = new Vector(maxConnections);
		System.out.println("Server settings:\n\tPort=" + port
				+ "\n\tMax Backlog=" + backlog + "\n\tMax Connections="
				+ maxConnections + "\n\tHost File=" + hostfile
				+ "\n\tSound File=" + soundfile);
		createHostList();
		try {
			URL sound = new URL(soundfile);
			connectSound = Applet.newAudioClip(sound);
		} catch (Exception e) {
			e.printStackTrace();
		}
		this.port = port;
		Thread t = new Thread(this);
		t.start();
	}
	private void createHostList() {
		File hostFile = new File(hostfile);
		try {
			System.out.println("Attempting to read hostfile hosts.txt: ");
			FileInputStream fis = new FileInputStream(hostFile);
			InputStreamReader isr = new InputStreamReader(fis);
			BufferedReader br = new BufferedReader(isr);
			String aLine = null;
			while ((aLine = br.readLine()) != null) {
				int spaceIndex = aLine.indexOf(' ');
				if (spaceIndex == -1) {
					System.out.println("Invalid line in host file: " + aLine);
					continue;
				}
				String host = aLine.substring(0, spaceIndex);
				String student = aLine.substring(spaceIndex + 1);
				System.out.println("Read: " + student + "@" + host);
				hostInfo.put(host, student);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	public void run() {
		ServerSocket serverSocket = null;
		Socket communicationSocket;
		try {
			System.out.println("Attempting to start server...");
			serverSocket = new ServerSocket(port, backlog);
		} catch (IOException e) {
			System.out.println("Error starting server: Could not open port "
					+ port);
			e.printStackTrace();
			System.exit(-1);
		}
		System.out.println("Started server on port " + port);
		// Run the listen/accept loop forever
		while (true) {
			try {
				// Wait here and listen for a connection
				communicationSocket = serverSocket.accept();
				HandleConnection(communicationSocket);
			} catch (Exception e) {
				System.out.println("Unable to spawn child socket.");
				e.printStackTrace();
			}
		}
	}

	public void HandleConnection(Socket connection) {
		synchronized (this) {
			while (numConnections == maxConnections) {
				try {
					wait();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}
		numConnections++;
		Connection con = new Connection(connection);
		Thread t = new Thread(con);
		t.start();
		connections.addElement(con);
	}

	public synchronized void connectionClosed(Connection connection) {
		connections.removeElement(connection);
		numConnections--;
		notify();
	}

	public void sendToAllClients(String message) {
		Enumeration cons = connections.elements();
		while (cons.hasMoreElements()) {
			Connection c = (Connection) cons.nextElement();
			c.sendMessage(message);
		}
	}
	class Connection implements Runnable {
		private Socket communicationSocket = null;
		private OutputStreamWriter out = null;
		private BufferedReader in = null;
		public void run() {
			OutputStream socketOutput = null;
			InputStream socketInput = null;
			try {
				socketOutput = communicationSocket.getOutputStream();
				out = new OutputStreamWriter(socketOutput);
				socketInput = communicationSocket.getInputStream();
				in = new BufferedReader(new InputStreamReader(socketInput));
				InetAddress address = communicationSocket.getInetAddress();
				String hostname = address.getHostName();
				String welcome = "Connection made from host: " + hostname
						+ "\nEverybody say hello";
				String student = (String) (hostInfo.get(hostname));
				if (student != null)
					welcome += " to " + student;
				welcome += "!\n";
				ChatServer.this.sendToAllClients(welcome);
				System.out.println("Connection made " + student + "@"
						+ hostname);
				sendMessage("Welcome " + student + " the passphrase is "
						+ magic + "\n");
				String input = null;

				while ((input = in.readLine()) != null) {
					if (input.indexOf(magic) != -1 && connectSound != null) {
						connectSound.play();
						sendMessage("Congratulations " + student
								+ " you sent the passphrase!\n");
						System.out.println(student + " sent the passphrase!");
					} else
						ChatServer.this.sendToAllClients(input + "\n");
				}
			} catch (Exception e) {
			} finally {
				try {
					if (in != null)
						in.close();
					if (out != null)
						out.close();
					communicationSocket.close();
				} catch (Exception e) {
					e.printStackTrace();
				}
				ChatServer.this.connectionClosed(this);
			}
		}
		public Connection(Socket s) {
			communicationSocket = s;
		}
		public void sendMessage(String message) {
			try {
				out.write(message);
				out.flush();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

}
客户端

import java.awt.*;
import java.io.*;
import java.net.*;
import java.awt.event.*;
public class ChatRoom {
	private TextArea outPut;
	private TextField inPut;
	private Button sendButton;
	private Button quitButton;
	private Choice namesList;
	private MenuItem quit;
	private MenuItem about;
	private Dialog aboutDialog;
	private Socket clientSocket = null;
	private BufferedReader in;
	private PrintStream out;
	public ChatRoom() {
		outPut = new TextArea(10, 50);
		inPut = new TextField(50);
		namesList = new Choice();
		sendButton = new Button("SEND");
		quitButton = new Button("QUIT");
		quit = new MenuItem("Quit");
		about = new MenuItem("About");
	}

	public void display() {
		Frame frame = new Frame();
		Panel p = new Panel();
		namesList.add("Grand Poobah");
		namesList.add("The Man");
		namesList.add("Java Geek");
		p.add(sendButton);
		p.add(quitButton);
		p.add(namesList);
		frame.add(outPut, BorderLayout.WEST);
		frame.add(p, BorderLayout.CENTER);
		frame.add(inPut, BorderLayout.SOUTH);
		MenuBar menuBar = new MenuBar();
		Menu file = new Menu("File");
		Menu help = new Menu("Help");
		
		file.add(quit);
		help.add(about);
		menuBar.add(file);
		menuBar.setHelpMenu(help);
		frame.setMenuBar(menuBar);
		frame.setVisible(true);
		frame.setSize(512, 241);

		aboutDialog = new AboutDialog(frame, "About", true);
		quit.addActionListener(new ActionListener(){

			public void actionPerformed(ActionEvent e) {
			out.println("User wang has been exit \n");  
				System.exit(0);
			}
			
		}
		);
		quitButton.addActionListener(new ActionListener(){

			public void actionPerformed(ActionEvent e) {
				out.println("User wang has been exit \n");
				System.exit(0);
			}
		});
         frame.addWindowListener(new WindowAdapter(){
        	 public void windowClosing(WindowEvent e){
        		 out.println("User wang has been exit \n");
        		 System.exit(0);
        		 
        	 }
         });
         inPut.addActionListener(new InputListener());
         sendButton.addActionListener(new SendListener());
         about.addActionListener(new AboutListener());
         docennect();
         
	}
	class AboutDialog extends Dialog implements ActionListener{
		public AboutDialog(Frame fr,String name,boolean statement){
			super(fr,name,statement);
			add(new Label("The ChatClient is a neat tool that allows you to talk " +
            "to other ChatClients via a ChatServer"),BorderLayout.NORTH);
			Button b = new Button("OK");
		      add(b,BorderLayout.SOUTH);
		      pack();
		      b.addActionListener(this);
		}

		public void actionPerformed(ActionEvent e) {
          aboutDialog.setVisible(false);			
		}
		
	}
	 
	class  AboutListener implements ActionListener{
	public void actionPerformed(ActionEvent e){
		aboutDialog.setVisible(true);        		
	}	
	}
	class InputListener implements ActionListener{
		public void actionPerformed(ActionEvent e) {
	          copyText();		
		}		
	}
     class SendListener implements ActionListener{
    	 public void actionPerformed(ActionEvent e) {
           copyText();    			
    		}	
}
public void copyText(){
	String text=inPut.getText();
	out.println(namesList.getSelectedItem()+":"+text);
	inPut.setText("");
}
	public void docennect(){
	     try{		clientSocket=new Socket("127.0.0.1",2000);
		in=new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
		out=new PrintStream(clientSocket.getOutputStream());
        out.println("User wang has been Login\n");
		Thread t=new Thread(new DisplayReader());
		t.start();
		}
    catch(Exception e1){
    	
		}
    	
    
	}
	class DisplayReader implements Runnable{
		private boolean keepListener=true;
		public void run() {
			while(keepListener){
				try{String nextLine=in.readLine();
    				outPut.append(nextLine+"\n");
				}
				catch(Exception e){
					keepListener=false;
					e.printStackTrace();
					
				}
				
			}
            			
		}

		
	}
	
	
	public static void main(String[] args) {
		ChatRoom chatRoom=new ChatRoom();
		  chatRoom.display();
	}
}