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.config.plugins.validation.validators;
18
19 import java.util.Collection;
20 import java.util.Map;
21
22 import org.apache.logging.log4j.Logger;
23 import org.apache.logging.log4j.core.config.plugins.validation.ConstraintValidator;
24 import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required;
25 import org.apache.logging.log4j.core.util.Assert;
26 import org.apache.logging.log4j.status.StatusLogger;
27
28 /**
29 * Validator that checks an object for emptiness. Emptiness is defined here as:
30 * <ul>
31 * <li>The value {@code null}</li>
32 * <li>An object of type {@link CharSequence} with length 0</li>
33 * <li>An empty array</li>
34 * <li>An empty {@link Collection}</li>
35 * <li>An empty {@link Map}</li>
36 * </ul>
37 *
38 * @since 2.1
39 */
40 public class RequiredValidator implements ConstraintValidator<Required> {
41
42 private static final Logger LOGGER = StatusLogger.getLogger();
43
44 private Required annotation;
45
46 @Override
47 public void initialize(final Required anAnnotation) {
48 this.annotation = anAnnotation;
49 }
50
51 @Override
52 public boolean isValid(final String name, final Object value) {
53 return Assert.isNonEmpty(value) || err(name);
54 }
55
56 private boolean err(final String name) {
57 LOGGER.error(annotation.message() + ": " + name);
58 return false;
59 }
60 }