Java Class for Wake On Lan

WakeOnLan.java

/* maiconio
 * http://pistach.es/
 */

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;

public class WakeOnLan {

	/**
	 * @param args
	 */
	public static void main(String[] args) {		
		if (args.length != 2){
			System.out.println("Usage: java WakeOnLan 12:34:56:78:90:AB 255.255.255.255");
			System.exit(0);
		}
		
		
		String macDest = args[0].toUpperCase();	//"12:34:56:78:90:AB";
		String ipDest = args[1];				//"255.255.255.255";
		int port = 9;
		
		DatagramSocket datagramSocket;
		try {
			datagramSocket = new DatagramSocket(port);
			datagramSocket.setBroadcast(true);
			
			String[] macPositions = macDest.split(":");
			byte[] macPositionsBuf = new byte[macPositions.length];
			
			for (int i=0; i< macPositions.length; i++){
				macPositionsBuf[i] = (byte) ((int) Integer.decode("0x"+macPositions[i])); 
			}
			
			byte[] buf = new byte[6 + ((macPositionsBuf.length) * 16)];
			for (int i=0; i < 6; i++){
				buf[i] = (byte) 0xFF; 
			}
				
			for (int i=0; i<16; i++){
				System.arraycopy(macPositionsBuf, 0, buf, (i*macPositionsBuf.length) + 6, macPositionsBuf.length);
			}

			InetSocketAddress inetSocketAddress = new InetSocketAddress(ipDest, 9);
			DatagramPacket p = new DatagramPacket(buf, buf.length, inetSocketAddress);
			datagramSocket.send(p);
			System.out.println("Magic packet sent!");
		} catch (SocketException e) {
			System.err.println("An error occurred while initializing the socket.");
			e.printStackTrace();
		} catch (IOException e) {
			System.err.println("An error occurred while sending the magic packet!");
			e.printStackTrace();
		}
	}
}