【android】Socket简单用法

    Socket通常也称做”套接字“，用于描述IP地址和端口，废话不多说，它就是网络通信过程中端点的抽象表示。值得一提的是，Java在包java.net中提供了两个类Socket和ServerSocket，分别用来表示双向连接的客户端和服务端。这是两个封装得非常好的类，使用起来很方便！

    下面将首先创建一个SocketServer的类作为服务端如下，该服务端实现了多线程机制，可以在特定端口处监听多个客户请求，一旦有客户请求，Server总是会创建一个服务纯种来服务新来的客户，而自己继续监听。程序中accept()是一个阻塞函数，所谓阻塞性方法就是说该方法被调用后将等待客户的请求，直到有一个客户启动并请求连接到相同的端口，然后accept()返回一个对应于客户的Socket。这时，客户方和服务方都建立了用于通信的Socket，接下来就是由各个Socket分别打开各自的输入、输出流。

• SocketServer类，服务器实现：

 1 package HA.Socket;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6  public class SocketServer {
 7     
 8     ServerSocket sever;
 9     
10     public SocketServer(int port){
11         try{
12             sever = new ServerSocket(port);
13         }catch(IOException e){
14             e.printStackTrace();
15         }
16     }
17     
18     public void beginListen(){
19         while(true){
20             try{
21                 final Socket socket = sever.accept();
22                 
23                 new Thread(new Runnable(){
24                     public void run(){
25                         BufferedReader in;
26                         try{
27                             in = new BufferedReader(new InputStreamReader(socket.getInputStream(),"UTF-8"));
28                             PrintWriter out = new PrintWriter(socket.getOutputStream());
29                             while (!socket.isClosed()){
30                                 String str;
31                                 str = in.readLine();
32                                 out.println("Hello!world!! " + str);
33                                 out.flush();
34                                 if (str == null || str.equals("end"))
35                                     break;
36                                 System.out.println(str);
37                             }
38                             socket.close();
39                         }catch(IOException e){
40                             e.printStackTrace();
41                         }
42                     }
43                 }).start();
44             }catch(IOException e){
45                 e.printStackTrace();
46             }
47         }
48     }
49 }

• SocketClient类，客户端实现：

 1 package HA.Socket;
 2 
 3 import java.io.*;
 4 import java.net.*;
 5 
 6  public class SocketClient {
 7     static Socket client;
 8     
 9     public SocketClient(String site, int port){
10         try{
11             client = new Socket(site,port);
12             System.out.println("Client is created! site:"+site+" port:"+port);
13         }catch (UnknownHostException e){
14             e.printStackTrace();
15         }catch (IOException e){
16             e.printStackTrace();
17         }
18     }
19     
20     public String sendMsg(String msg){
21         try{
22             BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
23             PrintWriter out = new PrintWriter(client.getOutputStream());
24             out.println(msg);
25             out.flush();
26             return in.readLine();
27         }catch(IOException e){
28             e.printStackTrace();
29         }
30         return "";
31     }
32     public void closeSocket(){
33         try{
34             client.close();
35         }catch(IOException e){
36             e.printStackTrace();
37         }
38     }
39     public static void main(String[] args) throws Exception{
40         
41     }
42 
43 }

    接下来就是来测试Socket通信了！

   先运行TestSocketServer类，打开服务端，在12345端口处监听！

1 package HA.Socket;
2 
3  public class TestSocketServer {
4     
5     public static void main(String[] argvs){
6         SocketServer server = new SocketServer(12345);
7         server.beginListen();
8     }
9 }

   再运行TestSocketClient类：

 1 package HA.Socket;
 2 
 3  public class TestSocketClient {
 4 
 5     public static void main(String[] args){
 6         
 7         SocketClient client = new SocketClient("127.0.0.1",12345);
 8         System.out.println(client.sendMsg("nimei1"));
 9         client.closeSocket();
10         
11         SocketClient client1 = new SocketClient("127.0.0.1",12345);
12         System.out.println(client1.sendMsg("nimei1111"));
13         client1.closeSocket();
14         
15         SocketClient client11 = new SocketClient("127.0.0.1",12345);
16         System.out.println(client11.sendMsg("nimei11111111"));
17         client11.closeSocket();
18         
19         SocketClient client111 = new SocketClient("127.0.0.1",12345);
20         System.out.println(client111.sendMsg("nimei11111111111111111"));
21         client111.closeSocket();
22         
23     }
24 }

 输出结果如下：

服务端：

Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei1
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei1111
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei11111111
Client is created! site:127.0.0.1 port:12345
Hello!world!! nimei11111111111111111

客户端：

nimei1
nimei1111
nimei11111111
nimei11111111111111111