title: Java convert a HEX String to a BigInt
body: <p>Hi am trying to convert a hex string such as String hexStr = "1b0ee1e3"; to a bigInt,
  ideally i'd like to convert hexStr to a bigint in its decimal form,</p>
  
  <p>I can convert a string to a bigInt w/o issues but when the string contains hex values
  i run into problems</p>