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 */
017package org.apache.logging.log4j.core.config.plugins.validation;
018
019import java.lang.annotation.Annotation;
020import java.lang.annotation.Documented;
021import java.lang.annotation.ElementType;
022import java.lang.annotation.Retention;
023import java.lang.annotation.RetentionPolicy;
024import java.lang.annotation.Target;
025
026/**
027 * Meta annotation to mark an annotation as a validation constraint. This annotation must specify a
028 * {@link ConstraintValidator} implementation class that has a default constructor.
029 *
030 * @since 2.1
031 */
032@Documented
033@Target(ElementType.ANNOTATION_TYPE)
034@Retention(RetentionPolicy.RUNTIME)
035public @interface Constraint {
036
037    /**
038     * {@link ConstraintValidator} class that implements the validation logic for the annotated constraint annotation.
039     */
040    Class<? extends ConstraintValidator<? extends Annotation>> value();
041}