基于UDP编程案例,发送端和接收端

先发送在接收

package com.iotek.tcpsocket;

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

public class UDPDemo1 {

	public static void main(String[] args) throws IOException {
		DatagramSocket socket=new DatagramSocket();
		String str="i love you";
		//把数据进行封装，封装到数据包中
		DatagramPacket packet=new DatagramPacket(str.getBytes(),str.length(),InetAddress.getByName("localhost"),8000);
		socket.send(packet);
		
		byte[] buff=new byte[100];
		DatagramPacket packet2=new DatagramPacket(buff,100);
		socket.receive(packet2);
		System.out.println(new String(buff,0,packet2.getLength()));
	}

}

先接收在发 送

package com.iotek.tcpsocket;

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

public class UDPDemo2 {

	public static void main(String[] args) throws IOException {
		DatagramSocket socket=new DatagramSocket(8000);
		byte[] buff=new byte[100];
		DatagramPacket packet=new DatagramPacket(buff, 100);
		socket.receive(packet);
		System.out.println(new String(buff, 0,packet.getLength()));
		
		String str="me too";
		DatagramPacket packet2=new DatagramPacket(
				str.getBytes(),str.length(),packet.getAddress(),packet.getPort());
		socket.send(packet2);
		socket.close();
	}

}