1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache license, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the license for the specific language governing permissions and
15 * limitations under the license.
16 */
17 package org.apache.logging.log4j.core.util;
18
19 /**
20 * Utility class providing common validation logic.
21 */
22 public final class Assert {
23 private Assert() {
24 }
25
26 /**
27 * Throws a {@code NullPointerException} if the specified parameter is
28 * {@code null}, otherwise returns the specified parameter.
29 * <p>
30 * On Java 7, just use {@code Objects.requireNonNull(T, String)}
31 * </p>
32 * <p>
33 * Usage:
34 * </p>
35 * <pre>
36 * // earlier you would write this:
37 * public SomeConstructor(Object param) {
38 * if (param == null) {
39 * throw new NullPointerException("param");
40 * }
41 * this.field = param;
42 * }
43 *
44 * // now you can do the same in one line:
45 * public SomeConstructor(Object param) {
46 * this.field = Assert.requireNonNull("param");
47 * }
48 * </pre>
49 *
50 * @param <T> the type of the parameter to check and return
51 * @param object the parameter to check
52 * @param message message to populate the NPE with if necessary
53 * @return the specified parameter
54 * @throws NullPointerException if {@code object} is {@code null}
55 */
56 public static <T> T requireNonNull(final T object, final String message) {
57 if (object == null) {
58 throw new NullPointerException(message);
59 }
60 return object;
61 }
62 }