java UDP实现一个聊天工具的示例代码

package Chat_UDP;

import java.io.IOException;
import java.util.Date;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.text.SimpleDateFormat;

public class Receive_Thread extends Thread {
 private static final int MAX_RECEIVE_BUFFER = 1024;
 private DatagramSocket server;
 private DatagramPacket packet;
 byte[] buffer = new byte[MAX_RECEIVE_BUFFER];
 
 public Receive_Thread(DatagramSocket server)
 {
  this.server = server;
  packet = new DatagramPacket(buffer, buffer.length);
 }
 
 @Override
 public void run() {
  try
  {
   while(true)
   {
    //接收数据包
    server.receive(packet);
    String s = new String(packet.getData(),packet.getOffset(),packet.getLength(),"UTF-8");
    Date day=new Date(); 
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
    if(packet.getPort() == 10001)
    	System.out.println("Tom"+packet.getAddress()+" 说:"+s+"\t"+df.format(day));
    else{
    	System.out.println("Jerry"+packet.getAddress()+" 说 :"+s+"\t"+df.format(day));
    }
    packet.setLength(buffer.length);
   }
  }
  catch(IOException e)
  {
   System.out.println("IOException");
  }
 }
}

package Chat_UDP;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.Scanner;

public class Send_Thread extends Thread{
 //发送的socket端
 private DatagramSocket sender = null;
 //待发送的目标地址
 private InetSocketAddress address = null;
 //从键盘输入
 Scanner scan = new Scanner(System.in);
 public Send_Thread(DatagramSocket sender,InetSocketAddress address)
 {
  this.sender = sender;
  this.address = address;
 }
 
 @Override
 public void run() {
  // TODO Auto-generated method stub
  try
  {
   while(true)
   {
    //输入待发送的内容
    String input = scan.nextLine();
    if(input.equals("exit"))
     break;
    byte[] data = null;
    data = input.getBytes("UTF-8");
    //创建UDP数据报
    DatagramPacket pack = new DatagramPacket(data, data.length,address);
    sender.send(pack); 
   }
   System.out.println("Exit!");
   
  }catch(IOException e)
  {
   System.out.println("IOException");
  }
 }

}

package Chat_UDP;
//杨丽冰 201831064402
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class Chat_Server {

 private static final int DEST_PORT = 8888;
 private static final int SEND_PORT = 10001;
 private static final int RECE_PORT = 9000;
 private static final String IP = "127.0.0.1";

 public static void main(String[] args)
 {
  try{
   Send_Thread send_thread = null;
   Receive_Thread rece_thread = null;
   InetSocketAddress address = null;
   //创建待接受数据包的目的机的端口号和IP地址
   address = new InetSocketAddress(IP, DEST_PORT);
   //创建发送的Socket端
   DatagramSocket sendsocket = new DatagramSocket(SEND_PORT);
   //创建接受的Socket端
   DatagramSocket recesocket = new DatagramSocket(RECE_PORT);
   //发送线程建立
   send_thread = new Send_Thread(sendsocket, address);
   //接受线程的建立
   rece_thread = new Receive_Thread(recesocket);
   send_thread.start();
   rece_thread.start();
  }catch(Exception e)
  {
   System.out.println("Exception!");
  }

 }

}

package Chat_UDP;
//杨丽冰 201831064402
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class Chat_Client {
	//声明端口号
 private static final int DEST_PORT = 9000;
 private static final int SEND_PORT = 10000;
 private static final int RECE_PORT = 8888;
 private static final String IP = "127.0.0.1";

 public static void main(String[] args)
 {
  try{
   Send_Thread send_thread = null;
   Receive_Thread rece_thread = null;
   InetSocketAddress address = null;
   //创建待接受数据包的目的机的端口号和IP地址
   address = new InetSocketAddress(IP, DEST_PORT);
   //创建发送的Socket端
   DatagramSocket sendsocket = new DatagramSocket(SEND_PORT);
   //创建接受的Socket端
   DatagramSocket recesocket = new DatagramSocket(RECE_PORT);
   //发送线程建立
   send_thread = new Send_Thread(sendsocket, address);
   //接受线程的建立
   rece_thread = new Receive_Thread(recesocket);
   send_thread.start();
   rece_thread.start();

  }catch(Exception e)
  {
   System.out.println("Exception!");
  }

 }

}