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.config.plugins.validation;
018    
019    import java.lang.annotation.Annotation;
020    
021    /**
022     * Interface that {@link Constraint} annotations must implement to perform validation logic.
023     *
024     * @param <A> the {@link Constraint} annotation this interface validates.
025     * @since 2.1
026     */
027    public interface ConstraintValidator<A extends Annotation> {
028    
029        /**
030         * Called before this validator is used with the constraint annotation value.
031         *
032         * @param annotation the annotation value this validator will be validating.
033         */
034        void initialize(A annotation);
035    
036        /**
037         * Indicates if the given value is valid.
038         *
039         * @param value the value to validate.
040         * @return {@code true} if the given value is valid.
041         */
042        boolean isValid(Object value);
043    }