java udp protocol used DatagramSocket class

 1 package com.temp;
 2 
 3 
 4 import org.junit.Test;
 5 
 6 import java.io.*;
 7 import java.net.DatagramPacket;
 8 import java.net.DatagramSocket;
 9 import java.net.InetSocketAddress;
10 
11 /**
12  * @author
13  * @date 2019/7/23
14  */
15 public class TestUdp {
16 
17     /**
18      * udp 发送数据：
19      * 1. DatagramSocket establish a connection, a connection port occupies
 20       * of DatagramPacket 2. Create a data packet, the data packet sent to the specified port occupied ports behavior does not occur
 21       * 3 send behavior
 22       * 4. Close connector
 23       *
 24       * @param 
25       * @return 
26 is       * @author 
27       * @date 2019/7/23 10:51
 28       * / 
29      @Test
 30      public  void udpSend () throws IOException {
 31 is          DatagramSocket = DatagramSocket new new DatagramSocket (9999 );
 32         MSG = String "MSG msg66666666666666!" ;
 33 is          of DatagramPacket DatagramPacket = new new of DatagramPacket (Msg.getBytes (), Msg.getBytes () length,. New new the InetSocketAddress ( "localhost", 6666 ));
 34 is          DatagramSocket.send (DatagramPacket);
 35          datagramSocket.close ();
 36      }
 37 [  
38 is      / ** 
39       * receiving UDP data:
 40       * 1. establish a connection DatagramSocket, occupy the port connection is established. Note: This port is connected to monitor received transmission of one transport port DatagramPacket
 41       * 2. Create a data packet DatagramPacket; storing the received data only, no longer listening port
 42       * 3. Receiving acts
 43      * 3.1 cycles into the receive process is carried out without receiving the transmission data congestion, received through the
 44       actual length data and the reception data received by the acquired 3.2 * actual packet acquisition datagramPacket
 45       * 4. Close connector
 46       *
 47       * @param 
48       * @return 
49       * @author 
50       * @date 2019/7/23 10:51
 51 is       * / 
52 is      @Test
 53 is      public  void udpRecive () throws IOException {
 54 is          DatagramSocket Client = new new DatagramSocket (6666);    / / STEP. 1 
55          byte [] bytes = new new byte[1024];
56         DatagramPacket datagramPacket = new DatagramPacket(bytes, bytes.length);
57         int count = 0;
58         while (count < 3) {
59             System.out.println("into circle!");
60             client.receive(datagramPacket);  //step 3.1
61             System.out.println("passed receive!");
62             byte[] data = datagramPacket.getData();     //step 3.2
63             int length = datagramPacket.getLength();    //3.2 STEP 
64  
65              System.out.println (COUNT + "Received Data Times:" + new new String (Data, 0 , length));
 66              COUNT ++ ;
 67          }
 68          System.out.println ( "reception times runs out, the program exits ! " );
 69          client.close ();
 70      }
 71 is  
72 }

 

Process Summary: establishing a connection (corresponding to the connection release operation), the establishment of a data storage objects (for, buffers, etc.), the specific operation (associated objects connected to the data storage, then perform specific behavior)