    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.util;
    018
    019    /**
    020     * Utility class providing common validation logic.
    021     */
    022    public final 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         * On Java 7, just use {@code Objects.requireNonNull(T, String)}
    031         * </p>
    032         * <p>
    033         * Usage:
    034         * </p>
    035         * <pre>
    036         * // earlier you would write this:
    037         * public SomeConstructor(Object param) {
    038         *     if (param == null) {
    039         *         throw new NullPointerException(&quot;param&quot;);
    040         *     }
    041         *     this.field = param;
    042         * }
    043         *
    044         * // now you can do the same in one line:
    045         * public SomeConstructor(Object param) {
    046         *     this.field = Assert.requireNonNull(&quot;param&quot;);
    047         * }
    048         * </pre>
    049         *
    050         * @param <T> the type of the parameter to check and return
    051         * @param object the parameter to check
    052         * @param message message to populate the NPE with if necessary
    053         * @return the specified parameter
    054         * @throws NullPointerException if {@code object} is {@code null}
    055         */
    056        public static <T> T requireNonNull(final T object, final String message) {
    057            if (object == null) {
    058                throw new NullPointerException(message);
    059            }
    060            return object;
    061        }
    062    }