客户端从键盘输入信息，发到服务端，服务端收到信息后，转成大写返回给客户端。

Server

package com.hbsi.net;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.net.ServerSocket;

import java.net.Socket;

public class TCPServer {

/**

  * @param args

  */

public static void main(String[] args) throws Exception{

  ServerSocket ss=new ServerSocket(3366);

  Socket s=ss.accept();

  System.out.println(s.getInetAddress().getHostAddress()+"......connection");

  InputStream in = s.getInputStream();

  BufferedReader brin=new BufferedReader(new InputStreamReader(in));

  BufferedWriter bwout=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));

 

  String line=null;

  while((line=brin.readLine())!=null){

   if(line.equals("over"))

    break;

   System.out.println("Client:"+line);

  

   bwout.write(line.toUpperCase());

   bwout.newLine();

   bwout.flush();

  }

  s.close();

  ss.close();

}

}

Client

package com.hbsi.net;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.net.Socket;

public class TCPClient {

/**

  * @param args

  */

public static void main(String[] args) throws Exception {

  Socket s = new Socket("192.168.49.2", 3366);

  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

  BufferedWriter bwout = new BufferedWriter(new OutputStreamWriter(s

    .getOutputStream()));

  BufferedReader brin = new BufferedReader(new InputStreamReader(s

    .getInputStream()));

  String line = null;

  while ((line = br.readLine()) != null) {

   if(line.equals("over"))

    break;

   bwout.write(line);

   bwout.newLine();

   bwout.flush();

   String str = brin.readLine();

   System.out.println("server:" + str);

  }

  br.close();

  s.close();

}

}