private int hexToByte(byte b){
switch (b) {
case '0':
    return 0;
case '1':
  return 1;
case '2':
return 2;
case '3':
return 3;
case '4':
return 4;
case '5':
return 5;
case '6':
return 6;
case '7':
return 7;
case '8':
return 8;
case '9':
return 9;
case 'A':
case 'a':
return 10;
case 'B':
case 'b':
return 11;
case 'C':
case 'c':
return 12;
case 'D':
case 'd':
return 13;
case 'E':
case 'e':
return 14;
case 'F':
case 'f':
return 15;
default :
throw new IllegalArgumentException("Switch error decoding URL");
}
}

private int hexToByte ( byte b ) { switch ( b ) { case '0' : return 0 ; case '1' : return 1 ; case '2' : return 2 ; case '3' : return 3 ; case '4' : return 4 ; case '5' : return 5 ; case '6' : return 6 ; case '7' : return 7 ; case '8' : return 8 ; case '9' : return 9 ; case 'A' : case 'a' : return 10 ; case 'B' : case 'b' : return 11 ; case 'C' : case 'c' : return 12 ; case 'D' : case 'd' : return 13 ; case 'E' : case 'e' : return 14 ; case 'F' : case 'f' : return 15 ; default : throw new IllegalArgumentException ( "Switch error decoding URL" ) ; } }
converts an ascii character representing a hexadecimal value into its integer equivalent .
