Here you can find the source of createBigInteger(final String str)
public static BigInteger createBigInteger(final String str)
//package com.java2s; /**/*from www . jav a 2 s . com*/ * Copyright (C) 2010-2016 Gordon Fraser, Andrea Arcuri and EvoSuite * contributors * * This file is part of EvoSuite. * * EvoSuite is free software: you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation, either version 3.0 of the License, or * (at your option) any later version. * * EvoSuite is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>. */ import java.math.BigInteger; public class Main { public static BigInteger createBigInteger(final String str) { if (str == null) { return null; } int pos = 0; // offset within string int radix = 10; boolean negate = false; // need to negate later? if (str.startsWith("-")) { negate = true; pos = 1; } if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex radix = 16; pos += 2; } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer) radix = 16; pos++; } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits radix = 8; pos++; } // default is to treat as decimal final BigInteger value = new BigInteger(str.substring(pos), radix); return negate ? value.negate() : value; } }