Converting byte from dec to hex

Question

Hi All,
I'm having a problem converting byte from decimal to hex - i need the following result:
if entered 127 (dec), the output should be 7f (hex).
The following method fails, of course because of NumberFormatException.
    private byte toHexByte(byte signedByte)
        int unsignedByte = signedByte;
        unsignedByte &= 0xff;
        String hexString = Integer.toHexString(unsignedByte);
        BigInteger bigInteger = new BigInteger(hexString);
        //byte hexByte = Byte.parseByte(hexString);
        return bigInteger.byteValue();
    }

Answer 1

get numberformatexception because a lot of hex digits cannot be transformed into int just like that (ie f is not a digit in decimal) heres some code that i used for a pdp11 assembler IDE... but this is for 16-bit 2s complement in binary/octal/decimal/hex , might be useful for reference as example though
    public static String getBase(short i, int base){
        String res = (i>=0)? Integer.toString((int)i,base)
                : Integer.toString((int)65536+i,base) + " ("+Integer.toString((int)i,base)+")";
       StringBuffer pad= new StringBuffer();
        for(int x = 0; x < 16 - res.length() ; x++){
            pad.append("0");
        res = pad.toString() + res;
        return res;
    }