chatb.java

java UDP聊天服务器及客户端

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.net.*;

public class chatb extends Frame implements ActionListener
{
	Label label = new Label("发言");
	Panel panel = new Panel();
	TextField tf = new TextField(10);
	TextArea ta = new TextArea();
	
	public chatb()
	{
		super("B方");
		setSize(250,250);
		panel.add(label);
		panel.add(tf);
		tf.addActionListener(this);
		add("North",panel);
		add("Center",ta);
		addWindowListener(new WindowAdapter()
		{ public void windowClosing(WindowEvent e){System.exit(0);}});
		show();
		//startup listener
		Listener listener = new Listener();
		Thread thread = new Thread(listener);
		thread.start();
	
	}
	
	public void actionPerformed(ActionEvent e)
	{
		//把要说的话发出去
		String str = tf.getText();
		byte[] buf = str.getBytes();
		tf.setText(null);
		ta.append("俺说:"+str);
		ta.append("\n");
		try{
			DatagramSocket socket = new DatagramSocket();
		    DatagramPacket packet = new DatagramPacket(buf,buf.length);
		    InetAddress remote_addr = InetAddress.getByName("localhost");
		    packet.setAddress(remote_addr);
		    //send to remote port 8888 
		    packet.setPort(8888);
		    socket.send(packet);
		  }
		  catch (UnknownHostException uhe){
		  	System.out.println("Unknown Host!");}
		  catch (IOException ioe){
		  	System.out.println("IO Error!");}
		
	}

    class Listener implements Runnable{
    	public void run(){
    	try
    	{
    		for(;;)
    		{
    		//监听本地端口8877
    		DatagramSocket socket = new DatagramSocket(8877);
    		DatagramPacket packet = new DatagramPacket(new byte[256], 256);
    		socket.receive(packet);
    		ByteArrayInputStream bin = new ByteArrayInputStream(packet.getData());
		    DataInputStream din = new DataInputStream(bin);
		    String str = din.readLine();
		    ta.append("对方说："+str);
		    ta.append("\n");
		    socket.close();
		  }
		    
		  }
		  catch (IOException ioe){
		  	System.out.println("IO Error!");}
        }
}		  
    
    public static void main(String args[])
    {
   	chatb b = new chatb();
   	}
}