Here you can find the source of sizeOf(Class cls)
public static int sizeOf(Class<?> cls)
//package com.java2s; /*//from w w w .j a va 2 s . com * Copyright (c) 2009 David Roberts <d@vidr.cc> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ public class Main { public static int sizeOf(Class<?> cls) { if (cls == boolean.class) return 1; if (cls == byte.class) return 1; if (cls == char.class) return 2; if (cls == short.class) return 2; if (cls == int.class) return 4; if (cls == long.class) return 8; if (cls == float.class) return 4; if (cls == double.class) return 8; throw new IllegalArgumentException("Cannot request size of non-primitive type"); } }