Here you can find the source of hexToBigInteger(String hex)
public static BigInteger hexToBigInteger(String hex)
//package com.java2s; //License from project: Apache License import java.math.BigInteger; public class Main { public static BigInteger hexToBigInteger(String hex) { return new BigInteger(hex, 16); }//from w w w.j a v a 2 s . c om }