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:12345Hello!world!! nimei1Client is created! site:127.0.0.1 port:12345Hello!world!! nimei1111Client is created! site:127.0.0.1 port:12345Hello!world!! nimei11111111Client is created! site:127.0.0.1 port:12345Hello!world!! nimei11111111111111111

客户端：

nimei1nimei1111nimei11111111nimei11111111111111111