java实现简单TCP聊天程序

package com.test.server;

import java.io.datainputstream;

import java.io.dataoutputstream;

import java.io.ioexception;

import java.net.serversocket;

import java.net.socket;

public class server {

  public static void main(string[] args) {

  new server().startserver();

  }

  public void startserver(){

  try {

   //服务器在9990端口监听客户端的连接

   serversocket ss = new serversocket( 9999 );

   system.out.println( "server is listening..." );

   while ( true ){

   //阻塞的accept方法，当一个客户端连接上，才会返回socket对象

   socket s = ss.accept();

   system.out.println( "a client has connected!" );

   //开启线程处理通信

   new communicatethread(s).start();

   }

  } catch (ioexception e) {

   e.printstacktrace();

  }

  }

  public class communicatethread extends thread{

  socket socket;

  datainputstream dis;

  dataoutputstream dos;

  public communicatethread(socket socket){

   this .socket = socket;

   try {

   dis = new datainputstream(socket.getinputstream());

   dos = new dataoutputstream(socket.getoutputstream());

   } catch (ioexception e) {

   e.printstacktrace();

   }

  }

  @override

  public void run() {

   super .run();

   //读取客户端发过来的消息

   string msg = null ;

   try {

   while ((msg = dis.readutf()) != null ){

    system.out.println( "client send msg ：" + msg);

    string replymsg = "server reply ： " + msg;

    dos.writeutf(replymsg);

    system.out.println( "server reply msg ：" + replymsg);

   }

   } catch (ioexception e) {

   e.printstacktrace();

   }

  }

  }

}

package com.test.client;

import java.io.datainputstream;

import java.io.dataoutputstream;

import java.io.ioexception;

import java.net.socket;

import java.util.scanner;

public class client {

  public static void main(string[] args) {

  new client().startclient();

  }

  public void startclient(){

  try {

   //连接到服务器

   socket socket = new socket( "localhost" , 9999 );

   datainputstream dis = new datainputstream(socket.getinputstream());

   dataoutputstream dos = new dataoutputstream(socket.getoutputstream());

   scanner scanner = new scanner(system.in);

   string line = null ;

   listenserverreply(dis);

   while ((line = scanner.nextline()) != null ){ //读取从键盘输入的一行

   dos.writeutf(line); //发给服务端

   system.out.println( "client send msg : " + line);

   }

  } catch (exception e) {

   e.printstacktrace();

  }

  }

  //监听服务端回复的消息

  public void listenserverreply( final datainputstream dis){

  new thread(){

   @override

   public void run() {

   super .run();

   string line = null ;

   try {

    while ((line = dis.readutf()) != null ){

    system.out.println( "client receive msg from server: " + line);

    }

   } catch (ioexception e) {

    e.printstacktrace();

   }

   }

  }.start();

  }

}