001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.aop;
020    
021    import java.lang.annotation.Annotation;
022    
023    /**
024     * Defines an AOP-framework-independent way of determining if an Annotation exists on a Method.
025     *
026     * @since 1.1
027     */
028    public interface AnnotationResolver {
029    
030        /**
031         * Returns an {@link Annotation} instance of the specified type based on the given
032         * {@link MethodInvocation MethodInvocation} argument, or {@code null} if no annotation
033         * of that type could be found. First checks the invoked method itself and if not found, 
034         * then the class for the existence of the same annotation. 
035         *
036         * @param mi the intercepted method to be invoked.
037         * @param clazz the annotation class of the annotation to find.
038         * @return the method's annotation of the specified type or {@code null} if no annotation of
039         *         that type could be found.
040         */
041        Annotation getAnnotation(MethodInvocation mi, Class<? extends Annotation> clazz);
042    }