Java tutorial
//package com.java2s; /** * Copyright (C) 2012-2015 52North Initiative for Geospatial Open Source * Software GmbH * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * If the program is linked with libraries which are licensed under one of * the following licenses, the combination of the program with the linked * library is not considered a "derivative work" of the program: * * - Apache License, version 2.0 * - Apache Software License, version 1.0 * - GNU Lesser General Public License, version 3 * - Mozilla Public License, versions 1.0, 1.1 and 2.0 * - Common Development and Distribution License (CDDL), version 1.0 * * Therefore the distribution of the program linked with libraries licensed * under the aforementioned licenses, is permitted by the copyright holders * if the distribution is compliant with both the GNU General Public * License version 2 and the aforementioned licenses. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General * Public License for more details. */ import java.util.Collection; import java.util.Map; public class Main { /** * Check if collection is not null and not empty * * @param collection * Collection to check * * @return empty or not */ public static <T> boolean isNotEmpty(Collection<T> collection) { return !isEmptyOrNull(collection); } /** * Check if collection is not null and not empty * * * @param map * Map to check * * @return <tt>false</tt>, if map is <tt>null</tt> or empty, else * <tt>true</tt>. */ public static <K, V> boolean isNotEmpty(Map<K, V> map) { return map != null && !map.isEmpty(); } public static <T> boolean isEmptyOrNull(Collection<T> collection) { return collection == null || collection.isEmpty(); } /** * Check if collection is not <tt>null</tt> and empty * * @param collection * Collection to check * * @return <tt>true</tt>, if collection is not null and empty, else * <tt>false</tt> */ public static <T> boolean isEmpty(Collection<T> collection) { return collection != null && collection.isEmpty(); } /** * Check if map is not <tt>null</tt> and empty * * @param map * map to check * * @return <tt>true</tt>, if map is not null and empty, else <tt>false</tt> */ public static <K, V> boolean isEmpty(Map<K, V> map) { return map != null && map.isEmpty(); } }