网络编程（一）

发送端：

package demo_03_15;

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

import demo_03_14.inetAddress;

public class UDPsend {
	/**
	 * @param args
	 * @throws IOException 
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		System.out.println("发送数据中…………");
		
		//第一步：创建UDPSocket
		DatagramSocket ds = new DatagramSocket();
		
		//第二步：创建InetAddress对象
		InetAddress ip = InetAddress.getByName("localhost");
		
		//第三步：创建UDP数据包
		String data = "fuck you java , php , python";
		byte[] buf = data.getBytes();
		DatagramPacket dp = new DatagramPacket(buf, buf.length, ip, 9000);
		
		//第四步：发送UDP数据包
		ds.send(dp);
		
		//第五步：关闭资源
		ds.close();
	}

}





接收端：

package demo_03_15;

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

public class UDPreceive {

	/**
	 * @param args
	 * @throws IOException 
	 */
	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		System.out.println("接收数据中…………");
		
		//第一步：创建接收udpsocket
		DatagramSocket ds = new DatagramSocket(10000);
		
		//第二步：创建存储包的udppacket
		byte[] buf = new byte[1024];
		DatagramPacket dp = new DatagramPacket(buf,buf.length);
		
		ds.receive(dp);  //阻塞式
		
		//第三步：解析接收到的udp包
		String host = dp.getAddress().getHostName();
		int port = dp.getPort();
		String data = new String(dp.getData(),0,dp.getLength());
		
		//第四步：关闭资源
		ds.close();
		
		System.out.println(host+" "+port+" "+data);
	}

}