UDP通信——局域网聊天室

package com.foot.lesson6;

import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Chat extends JFrame implements ActionListener,Runnable{
    private static final long serialVersionUID = -7231478529147734739L;
    private JTextArea ta1,ta2;
    private JScrollPane sp1,sp2;
    private JButton ok;
    private DatagramSocket ds;
    private String name;

//构造方法初始化
    public Chat(String title){
        super(title);
        ta1=new JTextArea();
        ta2=new JTextArea();
        sp1=new JScrollPane(ta1);
        sp2=new JScrollPane(ta2);
        ok=new JButton("send");
        try{
            ds=new DatagramSocket(9527);
        }catch(Exception e){}

        //界面设计
        getContentPane().setLayout(null);
        setBounds(312,84,400,550);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setResizable(false);

        getContentPane().add(sp1);
        ta1.setEditable(false);
        ta1.setForeground(Color.BLUE);
        ta1.setFont(new Font("黑体",Font.PLAIN,16));
        ta1.setLineWrap(true);
        sp1.setBounds(30,30,340,200);

        getContentPane().add(sp2);
        ta2.setForeground(Color.BLUE);
        ta2.setFont(new Font("黑体",Font.PLAIN,16));
        ta2.setLineWrap(true);
        sp2.setBounds(30,250,340,200);
        ta2.setToolTipText("按 ctrl+enter 可以快速发送消息");

        getContentPane().add(ok);
        ok.setBounds(290,470,80,25);
        ok.addActionListener(this);

        do{
            name=JOptionPane.showInputDialog(new JPanel(),"请输入你的名称，然后进入聊天室:");
            if(!name.equals(""))break;
        }while(true);
        setVisible(true);
    }

//接收
    public void run(){
        while(true){
            DatagramPacket dp=null;
            try{
                byte d[]=new byte[1024];
                dp=new DatagramPacket(d,1024);
                ds.receive(dp);
            }catch(Exception e){}
            String data=new String(dp.getData(),0,dp.getLength());
            ta1.append(data+"\n");
        }
    }

//发送
    public void sendMessage(){
        String data=ta2.getText();
        if(data.equals("")){
            JOptionPane.showMessageDialog(null,"发送信息不能为空.");
            return;
        }
        try{
            data=name+"说："+data;
            byte[] sdata=data.getBytes();
            InetAddress dest = InetAddress.getByName("255.255.255.255");**//该Ip地址代表要发广播**
            DatagramPacket dp = new DatagramPacket(sdata,sdata.length,dest,9527);//端口号：9527
            ds.send(dp);

        }catch(Exception de){}
        ta2.setText("");
    }

//点击send按钮发送消息
    public void actionPerformed(ActionEvent e){
        sendMessage();
    }
//执行入口
    public static void main(String args[]){
        new Thread(new Chat("chat")).start();
    }
}