java网络编程____UDP入门小demo

import java.io.*;
import java.net.*;

public class UDPServer{
	public static void main(String[] args)throws IOException{
		//初始化数据包
		DatagramSocket  datagramSocketServer = new DatagramSocket(5050);
		byte[] bytes = new byte[1024];
		//接收客户端数据包
		DatagramPacket receivePackage  = new DatagramPacket(bytes , bytes.length);
		datagramSocketServer.receive(receivePackage);
		
		//读取数据包内容
		String receiveStr = new String(receivePackage.getData() , 0 , receivePackage.getLength());
		System.out.println("Client　Say __:" + receiveStr);
		int port = receivePackage.getPort();
		InetAddress inetAddress = receivePackage.getAddress();
		String sendStr = "Server Say___: Copy that give you ResonseInfo....";
		byte[] sendBytes = sendStr.getBytes();
		DatagramPacket sendPacket = new DatagramPacket(sendBytes , sendBytes.length , inetAddress , port );

		datagramSocketServer.send(sendPacket);

		datagramSocketServer.close();
	}
}

//

客户端

 

import java.io.*;
import java.net.*;

/**
 * @author God
 */
public class UDPClient{
	public static void main(String[] args)throws IOException{
		DatagramSocket datagramSocketClient = new DatagramSocket();
		
		String sendStr = "Hello! I'm Client";
		byte[] sendBytes = sendStr.getBytes();
		InetAddress inetAddress = InetAddress.getByName("127.0.0.1");
		DatagramPacket sendPacket = new DatagramPacket(sendBytes ,sendBytes.length , inetAddress , 3000);

		datagramSocketClient.send(sendPacket);

		byte[] receiveBytes = new byte[100];
		DatagramPacket recvPacket = new DatagramPacket(receiveBytes , receiveBytes.length);
		datagramSocketClient.receive(recvPacket);
		String receiveStr = new String(recvPacket.getData() , 0 ,recvPacket.getLength());
		System.out.println("我是客户端收到你的信息____:"+receiveStr);
		datagramSocketClient.close();
	}
}