Here you can find the source of toDouble(Object obj)
public static double toDouble(Object obj)
//package com.java2s; /*L//from w w w .j av a2 s . co m * Copyright Washington University in St. Louis, SemanticBits, Persistent Systems, Krishagni. * * Distributed under the OSI-approved BSD 3-Clause License. * See http://ncip.github.com/wustl-common-package/LICENSE.txt for details. */ public class Main { public static double toDouble(Object obj) { double value = 0; if (obj == null) return value; else { Double dblObj = (Double) obj; value = dblObj.doubleValue(); return value; } } }