Here you can find the source of isPrimitiveWrapperClass(Class primitiveWrapperClass)
public static boolean isPrimitiveWrapperClass(Class primitiveWrapperClass)
//package com.java2s; /*/* w w w . ja v a2s .c o m*/ * JFox - The most lightweight Java EE Application Server! * more details please visit http://www.huihoo.org/jfox or http://www.jfox.org.cn. * * JFox is licenced and re-distributable under GNU LGPL. */ import java.util.HashMap; import java.util.Map; public class Main { private static Map<String, Class> primitiveStringToClass = new HashMap<String, Class>(); public static boolean isPrimitiveWrapperClass(Class primitiveWrapperClass) { return primitiveStringToClass.values().contains(primitiveWrapperClass); } }