What is the purpose of the code below?

try (DatagramSocket mySocket = new DatagramSocket()) {
    String text = "Hello";
    byte[] message = text.getBytes();
    DatagramPacket packetS = new DatagramPacket(message, message.length,
        InetAddress.getLocalHost(), 2000);
    mySocket.send(packetS);
    byte[] buffer = new byte[1024];
    DatagramPacket packetR = new DatagramPacket(buffer, buffer.length);
    mySocket.receive(packetR);            
    System.out.println("Received: " +
        new String(packetR.getData()).trim());
} catch (IOException e) {
    System.out.println(e);
}