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 + " is null"); 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 }