Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.lang.reflect.Array;

import java.util.Collection;

import java.util.Enumeration;

import java.util.Iterator;

import java.util.Map;

public class Main {
    /**
     * Checks if the specified collection/array/iterator is empty.
     * <p>
     * This method can handles objects as follows
     * <ul>
     * <li>Collection - via collection isEmpty
     * <li>Map - via map isEmpty
     * <li>Array - using array size
     * <li>Iterator - via hasNext
     * <li>Enumeration - via hasMoreElements
     * </ul>
     * <p>
     * Note: This method is named to avoid clashing with
     * {@link #isEmpty(Collection)}.
     *
     * @param object  the object to get the size of, may be null
     * @return true if empty or null
     * @throws IllegalArgumentException thrown if object is not recognised
     * @since 3.2
     */
    public static boolean sizeIsEmpty(final Object object) {
        if (object == null) {
            return true;
        } else if (object instanceof Collection<?>) {
            return ((Collection<?>) object).isEmpty();
        } else if (object instanceof Map<?, ?>) {
            return ((Map<?, ?>) object).isEmpty();
        } else if (object instanceof Object[]) {
            return ((Object[]) object).length == 0;
        } else if (object instanceof Iterator<?>) {
            return ((Iterator<?>) object).hasNext() == false;
        } else if (object instanceof Enumeration<?>) {
            return ((Enumeration<?>) object).hasMoreElements() == false;
        } else {
            try {
                return Array.getLength(object) == 0;
            } catch (final IllegalArgumentException ex) {
                throw new IllegalArgumentException("Unsupported object type: " + object.getClass().getName());
            }
        }
    }

    /**
     * Null-safe check if the specified collection is empty.
     * <p>
     * Null returns true.
     *
     * @param coll  the collection to check, may be null
     * @return true if empty or null
     * @since 3.2
     */
    public static boolean isEmpty(final Collection<?> coll) {
        return coll == null || coll.isEmpty();
    }
}