001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements. See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache license, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License. You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the license for the specific language governing permissions and
015     * limitations under the license.
016     */
017    package org.apache.logging.log4j.core.jmx;
018    
019    /**
020     * Utility class providing common validation logic.
021     */
022    public class Assert {
023        private Assert() {
024        }
025    
026        /**
027         * Throws a {@code NullPointerException} if the specified parameter is
028         * {@code null}, otherwise returns the specified parameter.
029         * <p>
030         * Usage:
031         * 
032         * <pre>
033         * // earlier you would write this:
034         * public SomeConstructor(Object param) {
035         *     if (param == null) {
036         *         throw new NullPointerException(name + &quot; is null&quot;);
037         *     }
038         *     this.field = param;
039         * }
040         * 
041         * // now you can do the same in one line:
042         * public SomeConstructor(Object param) {
043         *     this.field = Assert.isNotNull(param);
044         * }
045         * </pre>
046         * 
047         * @param checkMe the parameter to check
048         * @param name name of the parameter to use in the error message if
049         *            {@code null}
050         * @return the specified parameter
051         */
052        public static <T> T isNotNull(T checkMe, String name) {
053            if (checkMe == null) {
054                throw new NullPointerException(name + " is null");
055            }
056            return checkMe;
057        }
058    }