🚀 go-pugleaf

I wrote code like following,But when it run,it report:
java.net.SocketException: socket closed

	at java.net.PlainDatagramSocketImpl.receive(Native Method)

	at java.net.DatagramSocket.receive(DatagramSocket.java:392)

	at test.TT.main(tt.java:27)

what is matter?

code is :

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

public class TT {
    public static void main(String[] args) throws Exception{
        DatagramSocket socket = new DatagramSocket();
        socket.setSoTimeout(3000);
        byte[] buf = new byte[256];
        InetAddress address = InetAddress.getByName("150.100.100.101");
        DatagramPacket packet = new DatagramPacket(buf,buf.length,address,1111);
        socket.send(packet);
        packet = new DatagramPacket(buf,buf.length);

        try
        {
            socket.receive(packet);
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
        socket.close();
    }
}