java socket通訊（二）處理多個客戶端連接

    通過java socket通訊（一） 入門示例，就可以實現服務端和客戶端的socket通訊，但是上一個例子只能實現一個服務端和一個客戶端之間的通訊，如果有多個客戶端連接服務端，則需要通過多線程技術來實現。

服務器端----------------------------------------------------------------------------------------------------------------------------------------

socketServer：

package test;

import java.net.ServerSocket;
import java.net.Socket;

public class socketServer {
    public static void main(String [] args){
        ServerSocket ss = null;
        Socket sk = null;
        try{
            System.out.println("create server socket....");
            ss = new ServerSocket(3756);
            System.out.println("wait for a connection....");
            while(true)     //服務器端一直監聽這個端口，等待客戶端的連接
            {
              sk = ss.accept();  //當有客戶端連接時，產生阻塞               
              System.out.println("get a socket object...");
              
              new socketThread(sk).start();//新建一個socketThread處理這個客戶端的socket連接
          }
        }
        catch(Exception ex){
            System.out.println(ex.getMessage());
        }
        finally{
          try{
              if(ss != null){
                  ss.close();
              }
              if(sk != null){
                  sk.close();
              }
          }
          catch(Exception ex){
              System.out.println(ex.getMessage());
          }
        }
      }

}

socketThread：

package test;

import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.*;

public class socketThread extends Thread {
    public Socket socket;

    public socketThread(Socket socket) {
        this.socket = socket;
    }

    public void run() {
        PrintWriter pw = null;
        Calendar c;
        
        try {
            pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())));
             while(true)//服務器每隔3秒向客戶端發送當前時間信息
             {
                   Thread.sleep(3000);
                   c = Calendar.getInstance(); //獲取當前時間
                   pw.println("Server Time:"+c.getTime().toString()); 
                      pw.flush();
             }
             
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
        } finally {
            try {
                if (pw != null) {
                    pw.close();
                }
                if (socket != null) {
                    socket.close();
                }
            } catch (Exception ex) {
                System.out.println(ex.getMessage());
            }
        }
    }

}

 

客戶端----------------------------------------------------------------------------------------------------------------------------------------

socketClient：

package test;

import java.io.PrintWriter;
import java.net.Socket;
import java.io.InputStreamReader;
import java.io.BufferedReader;

public class socketClient {
    public static void main(String[] args) {
        Socket sk = null;
        BufferedReader br = null;
        try {
            sk = new Socket("localhost", 3756);
            
            br = new BufferedReader(new InputStreamReader(sk.getInputStream()));
             String line = null;
             while((line = br.readLine()) != null){
                 System.out.println("Msg from server:"+line);     //服務器端打印客戶端發送的信息數據
             }
        } catch (Exception ex) {
            System.out.println(ex.getMessage());
        } finally {
            try {
                if (sk != null) {
                    sk.close();
                }
                if (br != null) {
                    br.close();
                }
            } catch (Exception ex) {
                System.out.println(ex.getMessage());
            }
        }
    }

}

 

服務端啟動后，就會監聽3756端口，每當有一個客戶端請求時，就會新建一個socketThread來和客戶端進行通訊（每隔3秒鍾將服務端的時間發送到客戶端）