一、需求描述

实现UDP的通信

1.1 一发一收

1.1.1 ClientTest1

package com.itheima.udp;import java.net.*;import static java.net.InetAddress.*;//完成udp通信快速入门，实现一收一发
public class ClientTest1 {public static void main(String[] args) throws Exception {//创建客户端对象DatagramSocket socket = new DatagramSocket();//创建数据包对象封装要发出去的数据byte[] bytes = "我是快乐的客户端，我负责发送数据".getBytes();//4个参数代表：//1、要发送的数据//2、要发送的数据大小（字节数）//3、服务端的IP//4、服务端程序的端口号DatagramPacket packet = new DatagramPacket(bytes,bytes.length, getLocalHost(),6666);//开始发送数据包的数据出去socket.send(packet);System.out.println("客户端数据发送完毕！！！");//发送后关闭通信管道socket.close();}
}

1.1.2 ServerTest1

package com.itheima.udp;import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;public class ServerTest1  {public static void main(String[] args) throws Exception {System.out.println("-----服务端启动----------");//创建一个服务端对象，用来接收数据。需要注册端口DatagramSocket socket = new DatagramSocket(6666);//创建一个数据包对象，用于接收数据byte[] buffer = new byte[1024 * 64];DatagramPacket packet = new DatagramPacket(buffer,buffer.length);//开始接受数据socket.receive(packet);//获取本次数据包接收了多少数据int len = packet.getLength();String res = new String(buffer,0,len);System.out.println(res);//获取客户端的IP地址和端口号System.out.println(packet.getAddress().getHostAddress());System.out.println(packet.getPort());//释放资源socket.close();}
}

1.1.3 运行结果

 

1.2 多发多收

1.2.1 Client

package com.itheima.udp2;import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.util.Scanner;public class Client {public static void main(String[] args) throws Exception {//创建客户端对象DatagramSocket socket = new DatagramSocket();Scanner sc = new Scanner(System.in);while (true){//让用户输入要发送的消息System.out.println("请说：");String msg = sc.nextLine();//输入exit时退出if ("exit".equals(msg)) {System.out.println("欢迎下次光临！退出成功！！！");//关闭通道socket.close();break;}byte[] bytes = msg.getBytes();//创建发送数据的数据包DatagramPacket packet = new DatagramPacket(bytes,bytes.length,InetAddress.getLocalHost(),6666);//开始发送数据socket.send(packet);}//客户端数据发送完毕System.out.println("客户端数据发送完毕");}
}

1.2.2 Server

package com.itheima.udp2;import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;public class Server  {public static void main(String[] args) throws Exception {System.out.println("-----服务端启动----------");//创建一个服务端对象，用来接收数据。需要注册端口DatagramSocket socket = new DatagramSocket(6666);//创建一个数据包对象，用于接收数据byte[] buffer = new byte[1024 * 64];DatagramPacket packet = new DatagramPacket(buffer,buffer.length);while (true) {//开始接受数据socket.receive(packet);//获取本次数据包接收了多少数据int len = packet.getLength();String res = new String(buffer,0,len);System.out.println(res);//获取客户端的IP地址和端口号System.out.println(packet.getAddress().getHostAddress());System.out.println(packet.getPort());System.out.println("----------------------");}}
}

1.2.3 运行结果