UDP接收端和发送端_Socket编程

• UDP接收端

1. 1. 接收端启动文件

 1 import java.net.DatagramSocket;
 2 import java.net.SocketException;
 3
 4 public class Server {
 5
 6     public static void main(String[] args){
 7
 8         try {
 9
10             DatagramSocket socket = new DatagramSocket(9999);
11             ServerThread sThread = new ServerThread(socket);
12             sThread.start();
13
14         } catch (SocketException e) {
15
16             e.printStackTrace();
17         }
21     }
24 }

1. 1. 接收端线程文件

 1 import java.io.IOException;
 2 import java.net.DatagramPacket;
 3 import java.net.DatagramSocket;
 4 import java.net.InetAddress;
 5 import java.net.SocketException;
 6
 7 public class ServerThread extends Thread{
 8
 9     DatagramSocket socket = null;
10
11     public ServerThread(DatagramSocket socket) {
12         super();
13         this.socket = socket;
14     }
15
16     @Override
17     public void run() {
18         super.run();
19
20         try {
21 //            socket = new DatagramSocket(9999);
22
23             //建立数据包
24             byte []buf = new byte[1024];
25             DatagramPacket packet = new DatagramPacket(buf, buf.length);
26             System.out.println( "服务器开始运行...." );
27             while(true) {
28
29                 //接收客户端数据
30                 socket.receive(packet);
31
32                 //读取数据包的内容
33                 String data = new String(buf, 0, packet.getLength());
34                 System.out.println("我是服务器，接收到客户端的消息："+data);
35
36                 //发送,先获取客户端信息
37                 InetAddress address = packet.getAddress();
38                 int port = packet.getPort();
39                 byte []str = "服务器响应：你好".getBytes();
40                 DatagramPacket packet2 = new DatagramPacket(str, str.length,address,port);
41                 socket.send(packet2);
42
43             }
44
45         } catch (SocketException e) {
46             e.printStackTrace();
47         } catch (IOException e) {
48             // TODO Auto-generated catch block
49             e.printStackTrace();
50         }
51         finally {
52             socket.close();
53         }
54
55     }
56 }

• UDP发送端

 1 import java.io.IOException;
 2 import java.net.DatagramPacket;
 3 import java.net.DatagramSocket;
 4 import java.net.InetAddress;
 5 import java.net.SocketException;
 6 import java.text.SimpleDateFormat;
 7 import java.util.Date;
 8 import java.util.Scanner;
 9
10 public class Client {
11
12     public static void main(String[] args) throws IOException{
13
14         DatagramSocket socket = null;
15
16         try {
17
18             socket = new DatagramSocket();//udp不用端口号
19
20             while(true) {
21                 //时间
22                 Date myDate = new Date();
23                 SimpleDateFormat dFormat = new SimpleDateFormat("HH:mm:ss");
24                 //发送信息
25                 InetAddress address = InetAddress.getLocalHost();//取得服务器地址
26                 int port = 9999;
27
28                 Scanner input = new Scanner(System.in);//改为输入发送
29                 String inContent ="\r\n" +  dFormat.format(myDate) + "\r\n" +"黄哥哥说："+ input.next();
30
31                 byte []str = inContent.getBytes();
32                 DatagramPacket packet2 = new DatagramPacket(str, str.length,address,port);//InetAddress.getByName( "192.168.4.198" )
33                 socket.send(packet2);
34
35                 //接收信息
36                 //建立数据报包
37                 byte []buf = new byte[1024];
38                 DatagramPacket packet = new DatagramPacket(buf, buf.length);
39
40                 //接收服务器信息
41                 socket.receive(packet);
42
43                 //读取数据包的内容
44                 String data = new String(buf, 0, packet.getLength());
45                 System.out.println(data);
46
47             }
48         } catch (SocketException e) {
49             // TODO Auto-generated catch block
50             e.printStackTrace();
51         }finally {
52             //关闭
53             socket.close();
54         }
55
56     }
57 }

• 运行效果

1. 发送端发送消息，接收端回应

2.接收端收到的消息

原文地址：https://www.cnblogs.com/ynhwl/p/9434219.html