java TCP小程序

 1 package com.socket.tcp;
 2 
 3 import java.io.DataInputStream;
 4 import java.io.DataOutputStream;
 5 import java.io.IOException;
 6 import java.io.InputStream;
 7 import java.io.OutputStream;
 8 import java.net.ServerSocket;
 9 import java.net.Socket;
10 import java.net.UnknownHostException;
11 
12 import org.junit.Test;
13 
14 public class TestTCP {
15     @Test
16     public void testTCPServer() {
17         try {
18             ServerSocket ss = new ServerSocket(9999);
19             while (true) {// 需要不断的监听是否有客户端程序连接上来，所以需要不断地监控
20                 Socket socket = ss.accept();//阻塞式方法
21                 InputStream is = socket.getInputStream();
22                 DataInputStream dis = new DataInputStream(is);
23                 System.out.println(dis.readUTF());
24             }
25         } catch (IOException e) {
26             e.printStackTrace();
27         }
28     }
29 
30     @Test
31     public void testTCPClient() {
32         try {
33             Socket client = new Socket("127.0.0.1", 9999);
34             OutputStream os = client.getOutputStream();
35             DataOutputStream dos = new DataOutputStream(os);
36             dos.writeUTF("Hello Server");
37             dos.flush();
38             dos.close();
39 
40         } catch (UnknownHostException e) {
41             e.printStackTrace();
42         } catch (IOException e) {
43             e.printStackTrace();
44         }
45     }
46 
47 }