UDP/IP协议的网络编程

//127.0.0.1是本机IP地址

package lianxi1;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

import org.junit.Test;

public class TestUDP1 {
@Test
  public void send(){
    DatagramSocket ds = null;
    try {
        ds = new DatagramSocket();
        String str = "我是UDP数据报";
        byte[] b = str.getBytes();
        DatagramPacket dp = new DatagramPacket(b, 0, b.length, InetAddress
                .getByName("127.0.0.1"), 9910);
        ds.send(dp);
    } catch (Exception e) {
        // TODO: handle exception
    }
    if(ds!=null){
        ds.close();
        
    }
    
}

@Test
  public void receive(){
    DatagramSocket ds = null;
    try {
        ds = new DatagramSocket(9910);
        byte[] b = new byte[200];
        DatagramPacket dp = new DatagramPacket(b, 0, b.length);
        ds.receive(dp);
        String str = new String(dp.getData(),0,dp.getLength());
        System.out.println(str);
    } catch (Exception e) {
        // TODO: handle exception
    }
    if(ds!=null){
        ds.close();
    }
}
        
}