java tcp 端口监听

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.InetAddress;import java.net.ServerSocket;import java.net.Socket;public class Server extends ServerSocket {    publicServer(int serverPort) throws IOException {      // 用指定的端口构造一个ServerSocket      super(serverPort);      try {         while (true) {            // 监听一端口，等待客户接入            Socket socket = accept();            // 将会话交给线程处理            new ServerThread(socket);         }      } catch (IOException e) {         e.printStackTrace();      } finally {         close(); // 关闭监听端口      }    }    //inner-class ServerThread    classServerThread extends Thread {      private Socket socket;      private BufferedReader in;      private PrintWriter out;      // Ready to conversation      public ServerThread(Socket s) throws IOException{         this.socket = s;         // 构造该会话中的输入输出流         in = new BufferedReader(newInputStreamReader(socket               .getInputStream(), "GB2312"));         out = new PrintWriter(socket.getOutputStream(),true);         start();      }      // Execute conversation      public void run() {         try {            // Communicate with client until "bye "received.            while (true) {               // 通过输入流接收客户端信息               String line = in.readLine();               if (line == null || "".equals(line.trim())) { //是否终止会话                  break;               }               System.out.println("Received  message: " + line);               // 通过输出流向客户端发送信息               out.println(line);               out.flush();            }            out.close();            in.close();            socket.close();         } catch (IOException e) {            e.printStackTrace();         }      }    }    // mainmethod    publicstatic void main(String[] args) throws IOException {      new Server(2088);    }}