public static String bytesToHex(byte[] bytes) {
	    final char[] hexArray = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
	    char[] hexChars = new char[bytes.length * 2];
	    int v;
	    for ( int j = 0; j < bytes.length; j++ ) {
	        v = bytes[j] & 0xFF;
	        hexChars[j * 2] = hexArray[v >>> 4];
	        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
	    }
	    return new String(hexChars);
	}