前面的文章《Java Socket实现单线程通信的方法示例》说到怎样写一个最简单的Java Socket通信，但是文章中的例子有一个问题就是Server只能接受一个Client请求，当第一个Client连接后就占据了这个位置，后续Client不能再继续连接，所以需要做些改动，当Server没接受到一个Client连接请求之后，都把处理流程放到一个独立的线程里去运行，然后等待下一个Client连接请求，这样就不会阻塞Server端接收请求了。每个独立运行的程序在使用完Socket对象之后要将其关闭。代码如下：

package com.googlecode.garbagecan.test.socket.sample2;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class MyServer {
  public static void main(String[] args) throws IOException {
    ServerSocket server = new ServerSocket(10000);
    while (true) {
      Socket socket = server.accept();
      invoke(socket);
    }
  }
  private static void invoke(final Socket client) throws IOException {
    new Thread(new Runnable() {
      public void run() {
        BufferedReader in = null;
        PrintWriter out = null;
        try {
          in = new BufferedReader(new InputStreamReader(client.getInputStream()));
          out = new PrintWriter(client.getOutputStream());
          while (true) {
            String msg = in.readLine();
            System.out.println(msg);
            out.println("Server received " + msg);
            out.flush();
            if (msg.equals("bye")) {
              break;
            }
          }
        } catch(IOException ex) {
          ex.printStackTrace();
        } finally {
          try {
            in.close();
          } catch (Exception e) {}
          try {
            out.close();
          } catch (Exception e) {}
          try {
            client.close();
          } catch (Exception e) {}
        }
      }
    }).start();
  }
}

下面是Client程序代码：

package com.googlecode.garbagecan.test.socket.sample2;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
public class MyClient {
  public static void main(String[] args) throws Exception {
    Socket socket = new Socket("localhost", 10000);
    BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    PrintWriter out = new PrintWriter(socket.getOutputStream());
    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    while (true) {
      String msg = reader.readLine();
      out.println(msg);
      out.flush();
      if (msg.equals("bye")) {
        break;
      }
      System.out.println(in.readLine());
    }
    socket.close();
  }
}

测试，首先运行MyServer类，然后运行两个MyClient类，然后分别在每个MyClient的提示符下输入字符串，就可以看到Server可以分别接收处理每个Client的请求了。