Here you can find the source of toBigInteger(byte[] bytes)
public static BigInteger toBigInteger(byte[] bytes)
//package com.java2s; //License from project: Open Source License import java.math.BigInteger; import java.nio.ByteBuffer; public class Main { public static BigInteger toBigInteger(byte[] bytes) { return new BigInteger(bytes); }//from w w w . j a va 2 s . c om public static BigInteger toBigInteger(ByteBuffer buffer) { return new BigInteger(buffer.array()); } }