code: public static String bytesToHex(byte[] bytes, int size) {
  		size=Math.min(bytes.length, size);
  	    char[] hexChars = new char[size * 2];
  	    for ( int j = 0; j < size; j++ ) {
  	        int v = bytes[j] & 0xFF;
  	        hexChars[j * 2] = hexArray[v >>> 4];
  	        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
  	    }
  	    return new String(hexChars);
  	}
docs: Bytes to hex.
  
  @param bytes the bytes
  @param size the size
  @return the string