经典 socket通讯 -- 已验证

[tcp通信]

来源：不详；

client：

1. package com.defonds.socket.begin;  
2.   
3. import java.io.BufferedReader;  
4. import java.io.DataInputStream;  
5. import java.io.DataOutputStream;  
6. import java.io.IOException;  
7. import java.io.InputStreamReader;  
8. import java.net.Socket;  
9.   
10. public class Client {  
11.     public static final String IP_ADDR = "localhost";//服务器地址   
12.     public static final int PORT = 12345;//服务器端口号    
13.       
14.     public static void main(String[] args) {    
15.         System.out.println("客户端启动...");    
16.         System.out.println("当接收到服务器端字符为 "OK" 的时候, 客户端将终止 ");   
17.         while (true) {    
18.             Socket socket = null;  
19.             try {  
20.                 //创建一个流套接字并将其连接到指定主机上的指定端口号  
21.                 socket = new Socket(IP_ADDR, PORT);    
22.                     
23.                 //读取服务器端数据    
24.                 DataInputStream input = new DataInputStream(socket.getInputStream());    
25.                 //向服务器端发送数据    
26.                 DataOutputStream out = new DataOutputStream(socket.getOutputStream());    
27.                 System.out.print("请输入:  ");    
28.                 String str = new BufferedReader(new InputStreamReader(System.in)).readLine();    
29.                 out.writeUTF(str);    
30.                     
31.                 String ret = input.readUTF();     
32.                 System.out.println("服务器端返回过来的是: " + ret);    
33.                 // 如接收到 "OK" 则断开连接    
34.                 if ("OK".equals(ret)) {    
35.                     System.out.println("客户端将关闭连接");    
36.                     Thread.sleep(500);    
37.                     break;    
38.                 }    
39.                   
40.                 out.close();  
41.                 input.close();  
42.             } catch (Exception e) {  
43.                 System.out.println("客户端异常:" + e.getMessage());   
44.             } finally {  
45.                 if (socket != null) {  
46.                     try {  
47.                         socket.close();  
48.                     } catch (IOException e) {  
49.                         socket = null;   
50.                         System.out.println("客户端 finally 异常:" + e.getMessage());   
51.                     }  
52.                 }  
53.             }  
54.         }    
55.     }    
56. }    

服务端：

1. package com.defonds.socket.begin;  
2.   
3. import java.io.BufferedReader;  
4. import java.io.DataInputStream;  
5. import java.io.DataOutputStream;  
6. import java.io.InputStreamReader;  
7. import java.net.ServerSocket;  
8. import java.net.Socket;  
9.   
10. public class Server {  
11.     public static final int PORT = 12345;//监听的端口号     
12.       
13.     public static void main(String[] args) {    
14.         System.out.println("服务器启动... ");    
15.         Server server = new Server();    
16.         server.init();    
17.     }    
18.     
19.     public void init() {    
20.         try {    
21.             ServerSocket serverSocket = new ServerSocket(PORT);    
22.             while (true) {    
23.                 // 一旦有堵塞, 则表示服务器与客户端获得了连接    
24.                 Socket client = serverSocket.accept();    
25.                 // 处理这次连接    
26.                 new HandlerThread(client);    
27.             }    
28.         } catch (Exception e) {    
29.             System.out.println("服务器异常: " + e.getMessage());    
30.         }    
31.     }    
32.     
33.     private class HandlerThread implements Runnable {    
34.         private Socket socket;    
35.         public HandlerThread(Socket client) {    
36.             socket = client;    
37.             new Thread(this).start();    
38.         }    
39.     
40.         public void run() {    
41.             try {    
42.                 // 读取客户端数据    
43.                 DataInputStream input = new DataInputStream(socket.getInputStream());  
44.                 String clientInputStr = input.readUTF();//这里要注意和客户端输出流的写方法对应,否则会抛 EOFException  
45.                 // 处理客户端数据    
46.                 System.out.println("客户端发过来的内容:" + clientInputStr);    
47.     
48.                 // 向客户端回复信息    
49.                 DataOutputStream out = new DataOutputStream(socket.getOutputStream());    
50.                 System.out.print("请输入: ");    
51.                 // 发送键盘输入的一行    
52.                 String s = new BufferedReader(new InputStreamReader(System.in)).readLine();    
53.                 out.writeUTF(s);    
54.                   
55.                 out.close();    
56.                 input.close();    
57.             } catch (Exception e) {    
58.                 System.out.println("服务器 run 异常: " + e.getMessage());    
59.             } finally {    
60.                 if (socket != null) {    
61.                     try {    
62.                         socket.close();    
63.                     } catch (Exception e) {    
64.                         socket = null;    
65.                         System.out.println("服务端 finally 异常:" + e.getMessage());    
66.                     }    
67.                 }    
68.             }   
69.         }    
70.     }    
71. }