Here you can find the source of charToDigit(char c)
private static int charToDigit(char c)
//package com.java2s; //License from project: Open Source License public class Main { public static final String CODEX = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; private static int charToDigit(char c) { return CODEX.indexOf(c); }//from ww w.jav a 2 s. c om }