Java DatagramSocket listening on a broadcast address

I have written the simple test class which is meant to listen on Eth and receive all UDP packets, which go to port 5001:

public class Main {

  public static void main(String[] args) throws SocketException, UnknownHostException, IOException {
    DatagramSocket socket = new DatagramSocket(5001, InetAddress.getByName("255.255.255.255"));
    socket.setBroadcast(true);
    System.out.println("Listen on " + socket.getLocalAddress() + " from " + socket.getInetAddress() + " port " + socket.getBroadcast());
    byte[] buf = new byte[512];
    DatagramPacket packet = new DatagramPacket(buf, buf.length);
    while (true) {
      System.out.println("Waiting for data");
      socket.receive(packet);
      System.out.println("Data received");
    }
  }
}

It does not work anymore. It prints out Waiting for data and never continue. tcpdump shows me, that UDP broadcast packets come. What am I doing wrong? Thank you much.