java下udp的DatagramSocket 发送与接收

发送

package cn.stat.p4.ipdemo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketException;
import java.net.UnknownHostException;

public class netdemo {

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        //建立socket对像
        System.out.println("发送启动");
        senddata();

    }
    //发送数据
    public static void senddata() throws SocketException, UnknownHostException,
            IOException {
        DatagramSocket ds=new DatagramSocket();

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

        String line=null;

        while((line=bfr.readLine())!=null)
        {
            //封装要发送的数据
            if(line.equals("over"))
                break;
            byte[] buf=line.getBytes();
            DatagramPacket dp=new DatagramPacket(buf, buf.length,InetAddress.getByName("192.168.1.104"), 1000);

            //通过udp发送
            ds.send(dp);
        }

        ds.close();
    }

    //获得本机ip
    public static void getip() throws UnknownHostException {
        InetAddress ip =InetAddress.getLocalHost();

        System.out.println(ip.getHostAddress());
    }

}

接收

package cn.stat.p4.ipdemo;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class jieshoudemo {

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        while(true){
        jieshou();
        }

    }

    public static void jieshou() throws SocketException, IOException {
        System.out.println("接受启动");
        //建立接收socket
        DatagramSocket ds= new DatagramSocket(1000);
        //创建数据包
        byte[] buf=new byte[1024];
        DatagramPacket dp=new DatagramPacket(buf, buf.length);

        //使用接收方法将数据存储到数据包中
        ds.receive(dp);

        //通过数据包解析获取其中数据，如地址，端口，数据内容
        String ip=dp.getAddress().getHostAddress();
        int port=dp.getPort();
        String txt=new String(dp.getData(),0,dp.getLength());

        System.out.println(ip+":"+port+":"+txt);

        ds.close();
    }

}