UDP网络编程

package UDP;

import org.junit.Test;

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

public class UDPTest {
    @Test
    public void send() throws IOException {

//        1.
        DatagramSocket socket = new DatagramSocket();

//      将信息都放在DatagramPacket中
        String str = "我是UDP发送的信息";
        byte[] data = str.getBytes();
        InetAddress ip = InetAddress.getLocalHost();
        DatagramPacket packet = new DatagramPacket(data, 0, data.length, ip, 8090);

//        2.
        socket.send(packet);

        socket.close();

    }

    @Test
    public void receiver() throws IOException {

//        1.接收端指定端口号
        DatagramSocket socket = new DatagramSocket(8090);

        byte[] buffer = new byte[100];
        DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);

//          将接受的信息保存到buffer[]中
        socket.receive(packet);

        System.out.println(new String(packet.getData(),0,packet.getLength()));

        socket.close();


    }
}