聊天Demo

简单聊天功能，没有界面

思路：创建两个线程，分别为接收线程和发送线程，由主函数开启

1、发送

　　a、接收soket

　　b、建立一个数据包，并将键盘录入的数据封装到数据包内

　　c、调用socket的发送函数，将数据包发送给10000端口

2、接收

　　a、接收socket

　　b、建立接收数据包及缓冲区

　　c、调用socke的接收函数，监听1000端口

　　b、将接收到的ip地址及信息提取出来

代码如下：　　

import java.net.*;
import java.io.*;
class Send implements Runnable
    {
        private DatagramSocket ds;
        public Send(DatagramSocket ds)
        {
            this.ds=ds;
        }

        public void run()
        {
            try{
                BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));
                String line = null;
                while((line=bufr.readLine())!=null){
                if("886".equals(line))
                    break;
                byte[] buf = line.getBytes();
                DatagramPacket dp = new DatagramPacket(buf,buf.length,InetAddress.getByName("192.168.3.255"),10000);
                ds.send(dp);

                }

            }
            catch(Exception e){
                throw new RuntimeException("fasong");

            }
        }
    }

class Rece implements Runnable
    {
        private DatagramSocket ds;
        public Rece(DatagramSocket ds)
        {
            this.ds=ds;
        }

        public void run()
        {
            try{
            while(true){
                byte[] buf =new byte[1024];
                DatagramPacket dp =  new DatagramPacket(buf,buf.length);
                ds.receive(dp);
                String ip = dp.getAddress().getHostName();
                String data = new String(dp.getData(),0,dp.getLength());
                System.out.println(ip+": "+data);
            }}
            catch(Exception e){
                throw new RuntimeException("jieshou");

            }
        }
    }

class ChatDemo
{
        public static void main(String[] args)throws Exception
        {
            DatagramSocket sendSocket = new DatagramSocket();
            DatagramSocket receSocket = new DatagramSocket(10000);
            new Thread(new Send(sendSocket)).start();
            new Thread(new Rece(receSocket)).start();
        }
    }