Wake on lan

[david luis]

Hi,
I'm tryng to developp an application with java to WOL but doesn't works. The code:

String ipStr = "X.Y.Z.H";
        String macStr = "00:1B:FC:53:5A:11";

        try {
        	byte[] macBytes = getMacBytes(macStr);
        	byte[] bytes = new byte[6 + 16 * macBytes.length];
        	for (int i = 0; i < 6; i++) {
        			bytes[i] = (byte) 0xff;
        	}
        	for (int i = 6; i < bytes.length; i += macBytes.length) {
        			System.arraycopy(macBytes, 0, bytes, i, macBytes.length);
        	}

        	InetAddress address = InetAddress.getByName(ipStr);
        	DatagramPacket packet = new DatagramPacket(bytes,
        			bytes.length, address, PORT);
        	DatagramSocket socket = new DatagramSocket();
        	socket.send(packet);
        	socket.close();

        	System.out.println("Wake-on-LAN packet sent.");
        }
        catch (Exception e) {
        System.out.println("Failed to send Wake-on-LAN packet: " + e);
        System.exit(1);
        }

        }

        private static byte[] getMacBytes(String macStr) throws 
        	IllegalArgumentException {
        			byte[] bytes = new byte[6];
        			String[] hex = macStr.split("(\\:|\\-)");
        			if (hex.length != 6) {
        					throw new IllegalArgumentException("Invalid MAC address.");
        			}
        			try {
        					for (int i = 0; i < 6; i++) {
        							bytes[i] = (byte) Integer.parseInt(hex[i], 16);
        					}
        			} catch (NumberFormatException e) {
        				throw new IllegalArgumentException("Invalid hex digit in MAC address.");
        			}
        			return bytes;
        			}
	}

Could you help me please?
Many thanks and sorry for my english!