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：
package HA.Socket; import java.io.*; import java.net.*; public class SocketServer { ServerSocket sever; public SocketServer(int port){ try{ sever = new ServerSocket(port); }catch(IOException e){ e.printStackTrace(); } } public void beginListen(){ while(true){ try{ final Socket socket = sever.accept(); new Thread(new Runnable(){ public void run(){ BufferedReader in; try{ in = new BufferedReader(new InputStreamReader(socket.getInputStream(),"UTF-8")); PrintWriter out = new PrintWriter(socket.getOutputStream()); while (!socket.isClosed()){ String str; str = in.readLine(); out.println("Hello!world!! " + str); out.flush(); if (str == null || str.equals("end")) break; System.out.println(str); } socket.close(); }catch(IOException e){ e.printStackTrace(); } } }).start(); }catch(IOException e){ e.printStackTrace(); } } } } - SocketClient类，客户端实现：
package HA.Socket; import java.io.*; import java.net.*; public class SocketClient { static Socket client; public SocketClient(String site, int port){ try{ client = new Socket(site,port); System.out.println("Client is created! site:"+site+" port:"+port); }catch (UnknownHostException e){ e.printStackTrace(); }catch (IOException e){ e.printStackTrace(); } } public String sendMsg(String msg){ try{ BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream())); PrintWriter out = new PrintWriter(client.getOutputStream()); out.println(msg); out.flush(); return in.readLine(); }catch(IOException e){ e.printStackTrace(); } return ""; } public void closeSocket(){ try{ client.close(); }catch(IOException e){ e.printStackTrace(); } } public static void main(String[] args) throws Exception{ } }
接下来就是来测试Socket通信了！package HA.Socket; public class TestSocketServer { public static void main(String[] argvs){ SocketServer server = new SocketServer(12345); server.beginListen(); } }
- 再运行TestSocketClient类：
package HA.Socket; public class TestSocketClient { public static void main(String[] args){ SocketClient client = new SocketClient("127.0.0.1",12345); System.out.println(client.sendMsg("nimei1")); client.closeSocket(); SocketClient client1 = new SocketClient("127.0.0.1",12345); System.out.println(client1.sendMsg("nimei1111")); client1.closeSocket(); SocketClient client11 = new SocketClient("127.0.0.1",12345); System.out.println(client11.sendMsg("nimei11111111")); client11.closeSocket(); SocketClient client111 = new SocketClient("127.0.0.1",12345); System.out.println(client111.sendMsg("nimei11111111111111111")); client111.closeSocket(); } }- 输出如下
- 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：
nimei1nimei1111nimei11111111nimei11111111111111