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     * @author Les Hazlewood
031     * @since 0.9.0
032     */
033    public abstract class AnnotationHandler {
034    
035        /**
036         * The type of annotation this handler will process.
037         */
038        protected Class<? extends Annotation> annotationClass;
039    
040        /**
041         * Constructs an <code>AnnotationHandler</code> who processes annotations of the
042         * specified type.  Immediately calls {@link #setAnnotationClass(Class)}.
043         *
044         * @param annotationClass the type of annotation this handler will process.
045         */
046        public AnnotationHandler(Class<? extends Annotation> annotationClass) {
047            setAnnotationClass(annotationClass);
048        }
049    
050        /**
051         * Returns the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.
052         * <p/>
053         * This default implementation merely calls <code>{@link org.apache.shiro.SecurityUtils#getSubject SecurityUtils.getSubject()}</code>.
054         *
055         * @return the {@link org.apache.shiro.subject.Subject Subject} associated with the currently-executing code.
056         */
057        protected Subject getSubject() {
058            return SecurityUtils.getSubject();
059        }
060    
061        /**
062         * Sets the type of annotation this handler will inspect and process.
063         *
064         * @param annotationClass the type of annotation this handler will process.
065         * @throws IllegalArgumentException if the argument is <code>null</code>.
066         */
067        protected void setAnnotationClass(Class<? extends Annotation> annotationClass)
068                throws IllegalArgumentException {
069            if (annotationClass == null) {
070                String msg = "annotationClass argument cannot be null";
071                throw new IllegalArgumentException(msg);
072            }
073            this.annotationClass = annotationClass;
074        }
075    
076        /**
077         * Returns the type of annotation this handler inspects and processes.
078         *
079         * @return the type of annotation this handler inspects and processes.
080         */
081        public Class<? extends Annotation> getAnnotationClass() {
082            return this.annotationClass;
083        }
084    
085    }