package net.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerTester implements Runnable {

    @Override
    public void run() {
        ServerSocket server = null;
        try {
            server = new ServerSocket(5000);
            
            BufferedReader in = null;
            BufferedWriter out = null;
            while (true) {
                Socket socket = server.accept();
                
                in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                
                while (true) {
                    out.write("hello to client\r\n");
                    out.write("i am server\r\n");
                    out.write("bye\r\n");
                    out.flush();
                    if (in.readLine().trim().equals("exit")) {
                        break;
                    }
                }
                socket.close();
                System.err.println("第一次请求结束...按照你这个代码同时只能接受一个请求...");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (server != null) {
                try {
                    server.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

------解决方案--------------------
Java code

package net.test;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class SocketTester implements Runnable {

    @Override
    public void run() {
        Socket socket = null;

        BufferedReader in = null;
        BufferedWriter out = null;
        try {
            socket = new Socket("localhost", 5000);

            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));

            String line = null;
            while ((line = in.readLine()) != null) {
                if (line.trim().equals("bye")) {
                    break;
                } else {
                    System.out.println(line);
                }
            }
            out.write("exit\r\n");
            out.flush();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}