Testing with Live Devices

public class ByteArrayUtils {
 
	private ByteArrayUtils() {}
 
	public static byte[] fromHexString(final String encoded) {
	    if ((encoded.length() % 2) != 0)
	        throw new IllegalArgumentException("Input must contain " +
	        		"an even number of characters");
 
	    final byte result[] = new byte[encoded.length()/2];
 
	    StringBuffer buf = new StringBuffer(encoded);	    
	    for (int i = 0; i < buf.length(); i += 2) {
	        result[i/2] = (byte) Integer.parseInt(buf.substring(i, i+2), 16);
	    }
 
	    return result;
	}
 
    public static String toHexString(byte[] data) {
        if (data == null) return "";
 
        StringBuffer buf = new StringBuffer(data.length * 2);
        for (int i = 0; i < data.length; i++) {
        	String ch = Integer.toHexString(data[i] & 0xff);
        	if (ch.length() == 1) {
        		buf.append("0");
        	}
        	buf.append(ch);
        }
 
        return buf.toString();
    }
 
}