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    import org.apache.shiro.SecurityUtils;
024    import org.apache.shiro.subject.Subject;
025    
026    
027    /**
028     * Base support class for implementations that reads and processes JSR-175 annotations.
029     *
030     * @since 0.9.0
031     */
032    public abstract class AnnotationHandler {
033    
034        /**
035         * The type of annotation this handler will process.
036         */
037        protected Class<? extends Annotation> annotationClass;
038    
039        /**
040         * Constructs an <code>AnnotationHandler</code> who processes annotations of the
041         * specified type.  Immediately calls {@link #setAnnotationClass(Class)}.
042         *
043         * @param annotationClass the type of annotation this handler will process.
044         */
045        public AnnotationHandler(Class<? extends Annotation> annotationClass) {
046            setAnnotationClass(annotationClass);
047        }
048    
049        /**
050         * Returns the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.
051         * <p/>
052         * This default implementation merely calls <code>{@link org.apache.shiro.SecurityUtils#getSubject SecurityUtils.getSubject()}</code>.
053         *
054         * @return the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.
055         */
056        protected Subject getSubject() {
057            return SecurityUtils.getSubject();
058        }
059    
060        /**
061         * Sets the type of annotation this handler will inspect and process.
062         *
063         * @param annotationClass the type of annotation this handler will process.
064         * @throws IllegalArgumentException if the argument is <code>null</code>.
065         */
066        protected void setAnnotationClass(Class<? extends Annotation> annotationClass)
067                throws IllegalArgumentException {
068            if (annotationClass == null) {
069                String msg = "annotationClass argument cannot be null";
070                throw new IllegalArgumentException(msg);
071            }
072            this.annotationClass = annotationClass;
073        }
074    
075        /**
076         * Returns the type of annotation this handler inspects and processes.
077         *
078         * @return the type of annotation this handler inspects and processes.
079         */
080        public Class<? extends Annotation> getAnnotationClass() {
081            return this.annotationClass;
082        }
083    
084    }