java网络编程之UDP讲解

先上客户端代码

package com.test.net;

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

public class UDPClient {

	/**
	 *UDP客户端
	 */
	
	public static void main(String[] args) throws Exception {
		DatagramSocket socket=new DatagramSocket();
		String str="hello";
		byte[] buf=str.getBytes();
		
		DatagramPacket packet=new DatagramPacket(buf,buf.length,InetAddress.getByName("127.0.0.1"),1111);
		/*直接发包*/
		socket.send(packet);
	}

}

package com.test.net;

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

public class UDPServer {

	/**
	 *UDP服务器
	 */
	public static void main(String[] args) throws Exception {
		DatagramSocket socket=new DatagramSocket(1111);
		byte[] buf=new byte[256];
		DatagramPacket packet=new DatagramPacket(buf,buf.length);
		/*监听，阻塞*/
		socket.receive(packet);
		
		String received=new String(packet.getData());
		System.out.println(received);
		
	}

}

在服务器中，DatagramPacket的receive方法会阻塞，相当于监听，一直到监听到数据报为止。

输出结果

结果就是服务器端输出了hello。

java网络编程之UDP讲解

原文：http://blog.csdn.net/itbuluoge/article/details/39502989