001    /**
002     * Copyright (c) 2000-2011 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.spring.aop;
016    
017    import com.liferay.portal.kernel.util.MethodTargetClassKey;
018    
019    import java.lang.annotation.Annotation;
020    import java.lang.reflect.Method;
021    
022    import java.util.Map;
023    import java.util.concurrent.ConcurrentHashMap;
024    
025    import org.aopalliance.intercept.MethodInvocation;
026    
027    /**
028     * @author Shuyang Zhou
029     * @author Brian Wing Shun Chan
030     */
031    public abstract class AnnotationChainableMethodAdvice<T extends Annotation>
032            extends ChainableMethodAdvice {
033    
034            public AnnotationChainableMethodAdvice() {
035                    _nullAnnotation = getNullAnnotation();
036                    _annotationType = _nullAnnotation.annotationType();
037            }
038    
039            public abstract T getNullAnnotation();
040    
041            protected MethodTargetClassKey buildMethodTargetClassKey(
042                    MethodInvocation methodInvocation) {
043    
044                    Method method = methodInvocation.getMethod();
045    
046                    Class<?> targetClass = null;
047    
048                    Object thisObject = methodInvocation.getThis();
049    
050                    if (thisObject != null) {
051                            targetClass = thisObject.getClass();
052                    }
053    
054                    return new MethodTargetClassKey(method, targetClass);
055            }
056    
057            protected T findAnnotation(MethodTargetClassKey methodTargetClassKey){
058                    Annotation[] annotations = _annotations.get(methodTargetClassKey);
059    
060                    if (annotations != null) {
061                            return getAnnotation(annotations);
062                    }
063    
064                    Method method = methodTargetClassKey.getMethod();
065    
066                    Method targetMethod = methodTargetClassKey.getTargetMethod();
067    
068                    if (targetMethod != null) {
069                            annotations = targetMethod.getAnnotations();
070                    }
071    
072                    if ((annotations == null) || (annotations.length == 0)) {
073                            annotations = method.getAnnotations();
074                    }
075    
076                    if ((annotations == null) || (annotations.length == 0)) {
077                            annotations = _emptyAnnotations;
078                    }
079    
080                    _annotations.put(methodTargetClassKey, annotations);
081    
082                    return getAnnotation(annotations);
083            }
084    
085            protected T getAnnotation(Annotation[] annotations) {
086                    for(Annotation annotation : annotations) {
087                            if (annotation.annotationType() == _annotationType) {
088                                    return (T)annotation;
089                            }
090                    }
091    
092                    return _nullAnnotation;
093            }
094    
095            private static Map<MethodTargetClassKey, Annotation[]> _annotations =
096                    new ConcurrentHashMap<MethodTargetClassKey, Annotation[]>();
097            private static Annotation[] _emptyAnnotations = new Annotation[0];
098    
099            private Class<? extends Annotation> _annotationType;
100            private T _nullAnnotation;
101    
102    }