Here you can find the source of isDouble(BigDecimal number)
private static boolean isDouble(BigDecimal number)
//package com.java2s; //License from project: Apache License import java.math.BigDecimal; public class Main { private static boolean isDouble(BigDecimal number) { double doubleValue = number.doubleValue(); return (doubleValue != Double.NEGATIVE_INFINITY) && (doubleValue != Double.POSITIVE_INFINITY); }//from w ww . j a va 2 s . c o m }