Here you can find the source of convertHexDigit(byte b)
private static byte convertHexDigit(byte b)
//package com.java2s; //License from project: Open Source License public class Main { private static byte convertHexDigit(byte b) { if ((b >= '0') && (b <= '9')) { return (byte) (b - '0'); }/*www.j ava 2s . com*/ if ((b >= 'a') && (b <= 'f')) { return (byte) (b - 'a' + 10); } if ((b >= 'A') && (b <= 'F')) { return (byte) (b - 'A' + 10); } return 0; } }