Here you can find the source of isNumberType(Class> type)
public static boolean isNumberType(Class<?> type)
//package com.java2s; /*//from w w w . j a va 2 s.c o m * (c) Copyright 2007-2013 by Volker Bergmann. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, is permitted under the terms of the * GNU General Public License. * * For redistributing this software or a derivative work under a license other * than the GPL-compatible Free Software License as defined by the Free * Software Foundation or approved by OSI, you must first obtain a commercial * license to this software product from Volker Bergmann. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS, * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ import java.util.*; public class Main { /** * Map of integral Java number types */ private static Map<String, Class<?>> integralNumberTypeMap; /** * Map of decimal Java number types */ private static Map<String, Class<?>> decimalNumberTypeMap; public static boolean isNumberType(Class<?> type) { return (isIntegralNumberType(type) || isDecimalNumberType(type)); } public static boolean isIntegralNumberType(Class<?> type) { return isIntegralNumberType(type.getName()); } public static boolean isIntegralNumberType(String className) { return integralNumberTypeMap.containsKey(className); } public static boolean isDecimalNumberType(Class<?> type) { return isDecimalNumberType(type.getName()); } public static boolean isDecimalNumberType(String className) { return decimalNumberTypeMap.containsKey(className); } }