创建一个小窗口 并实现最简单交互

 

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

public class Demo3_MoreThread {

 /**
  * @param args
  */
 public static void main(String[] args) {
  new Receive().start();
  
  new Send().start();
 }

}

class Receive extends Thread {
 public void run() {
  try {
   DatagramSocket socket = new DatagramSocket(6666);  //创建Socket相当于创建码头
   DatagramPacket packet = new DatagramPacket(new byte[1024], 1024);//创建Packet相当于创建集装箱
   
   while(true) {
    socket.receive(packet);         //接货,接收数据
    
    byte[] arr = packet.getData();       //获取数据
    int len = packet.getLength();       //获取有效的字节个数
    String ip = packet.getAddress().getHostAddress();  //获取ip地址
    int port = packet.getPort();       //获取端口号
    System.out.println(ip + ":" + port + ":" + new String(arr,0,len));
   }
  } catch (IOException e) {
   
   e.printStackTrace();
  }
 }
}

class Send extends Thread {
 public void run() {
  try {
   Scanner sc = new Scanner(System.in);      //创建键盘录入对象
   DatagramSocket socket = new DatagramSocket();    //创建Socket相当于创建码头
   
   while(true) {
    String line = sc.nextLine();       //获取键盘录入的字符串
    if("quit".equals(line)) {
     break;
    }
    DatagramPacket packet =         //创建Packet相当于集装箱
      new DatagramPacket(line.getBytes(), line.getBytes().length, InetAddress.getByName("127.0.0.1"), 6666);
    socket.send(packet);         //发货,将数据发出去
   }
   socket.close();
  }  catch (IOException e) {
   
   e.printStackTrace();
  }  
 }
}