/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.aop.aspectj.annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;
import org.aopalliance.aop.Advice;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.DeclareParents;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.aop.Advisor;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.aspectj.AbstractAspectJAdvice;
import org.springframework.aop.aspectj.AspectJAfterAdvice;
import org.springframework.aop.aspectj.AspectJAfterReturningAdvice;
import org.springframework.aop.aspectj.AspectJAfterThrowingAdvice;
import org.springframework.aop.aspectj.AspectJAroundAdvice;
import org.springframework.aop.aspectj.AspectJExpressionPointcut;
import org.springframework.aop.aspectj.AspectJMethodBeforeAdvice;
import org.springframework.aop.aspectj.DeclareParentsAdvisor;
import org.springframework.aop.framework.AopConfigException;
import org.springframework.aop.support.DefaultPointcutAdvisor;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;
/**
* Factory that can create Spring AOP Advisors given AspectJ classes from
* classes honoring the AspectJ 5 annotation syntax, using reflection to
* invoke the corresponding advice methods.
*
* @author Rod Johnson
* @author Adrian Colyer
* @author Juergen Hoeller
* @author Ramnivas Laddad
* @since 2.0
*/
public class ReflectiveAspectJAdvisorFactory extends AbstractAspectJAdvisorFactory {
public List<Advisor> getAdvisors(MetadataAwareAspectInstanceFactory maaif) {
final Class<?> aspectClass = maaif.getAspectMetadata().getAspectClass();
final String aspectName = maaif.getAspectMetadata().getAspectName();
validate(aspectClass);
// We need to wrap the MetadataAwareAspectInstanceFactory with a decorator
// so that it will only instantiate once.
final MetadataAwareAspectInstanceFactory lazySingletonAspectInstanceFactory =
new LazySingletonAspectInstanceFactoryDecorator(maaif);
final List<Advisor> advisors = new LinkedList<Advisor>();
ReflectionUtils.doWithMethods(aspectClass, new ReflectionUtils.MethodCallback() {
public void doWith(Method method) throws IllegalArgumentException {
// Exclude pointcuts
if (AnnotationUtils.getAnnotation(method, Pointcut.class) == null) {
Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, advisors.size(), aspectName);
if (advisor != null) {
advisors.add(advisor);
}
}
}
});
// If it's a per target aspect, emit the dummy instantiating aspect.
if (!advisors.isEmpty() && lazySingletonAspectInstanceFactory.getAspectMetadata().isLazilyInstantiated()) {
Advisor instantiationAdvisor = new SyntheticInstantiationAdvisor(lazySingletonAspectInstanceFactory);
advisors.add(0, instantiationAdvisor);
}
// Find introduction fields.
for (Field field : aspectClass.getDeclaredFields()) {
Advisor advisor = getDeclareParentsAdvisor(field);
if (advisor != null) {
advisors.add(advisor);
}
}
return advisors;
}
/**
* Build a {@link org.springframework.aop.aspectj.DeclareParentsAdvisor}
* for the given introduction field.
* <p>Resulting Advisors will need to be evaluated for targets.
* @param introductionField the field to introspect
* @return <code>null</code> if not an Advisor
*/
private Advisor getDeclareParentsAdvisor(Field introductionField) {
DeclareParents declareParents = (DeclareParents) introductionField.getAnnotation(DeclareParents.class);
if (declareParents == null) {
// Not an introduction field
return null;
}
if (DeclareParents.class.equals(declareParents.defaultImpl())) {
// This is what comes back if it wasn't set. This seems bizarre...
// TODO this restriction possibly should be relaxed
throw new IllegalStateException("defaultImpl must be set on DeclareParents");
}
return new DeclareParentsAdvisor(
introductionField.getType(), declareParents.value(), declareParents.defaultImpl());
}
public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aif,
int declarationOrderInAspect, String aspectName) {
validate(aif.getAspectMetadata().getAspectClass());
AspectJExpressionPointcut ajexp =
getPointcut(candidateAdviceMethod, aif.getAspectMetadata().getAspectClass());
if (ajexp == null) {
return null;
}
return new InstantiationModelAwarePointcutAdvisorImpl(
this, ajexp, aif, candidateAdviceMethod, declarationOrderInAspect, aspectName);
}
private AspectJExpressionPointcut getPointcut(Method candidateAdviceMethod, Class<?> candidateAspectClass) {
AspectJAnnotation<?> aspectJAnnotation =
AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);
if (aspectJAnnotation == null) {
return null;
}
AspectJExpressionPointcut ajexp =
new AspectJExpressionPointcut(candidateAspectClass, new String[0], new Class[0]);
ajexp.setExpression(aspectJAnnotation.getPointcutExpression());
return ajexp;
}
public Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut ajexp,
MetadataAwareAspectInstanceFactory aif, int declarationOrderInAspect, String aspectName) {
Class<?> candidateAspectClass = aif.getAspectMetadata().getAspectClass();
validate(candidateAspectClass);
AspectJAnnotation<?> aspectJAnnotation =
AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);
if (aspectJAnnotation == null) {
return null;
}
// If we get here, we know we have an AspectJ method.
// Check that it's an AspectJ-annotated class
if (!isAspect(candidateAspectClass)) {
throw new AopConfigException("Advice must be declared inside an aspect type: " +
"Offending method '" + candidateAdviceMethod + "' in class [" +
candidateAspectClass.getName() + "]");
}
if (logger.isDebugEnabled()) {
logger.debug("Found AspectJ method: " + candidateAdviceMethod);
}
AbstractAspectJAdvice springAdvice;
switch (aspectJAnnotation.getAnnotationType()) {
case AtBefore:
springAdvice = new AspectJMethodBeforeAdvice(candidateAdviceMethod, ajexp, aif);
break;
case AtAfter:
springAdvice = new AspectJAfterAdvice(candidateAdviceMethod, ajexp, aif);
break;
case AtAfterReturning:
springAdvice = new AspectJAfterReturningAdvice(candidateAdviceMethod, ajexp, aif);
AfterReturning afterReturningAnnotation = (AfterReturning) aspectJAnnotation.getAnnotation();
if (StringUtils.hasText(afterReturningAnnotation.returning())) {
springAdvice.setReturningName(afterReturningAnnotation.returning());
}
break;
case AtAfterThrowing:
springAdvice = new AspectJAfterThrowingAdvice(candidateAdviceMethod, ajexp, aif);
AfterThrowing afterThrowingAnnotation = (AfterThrowing) aspectJAnnotation.getAnnotation();
if (StringUtils.hasText(afterThrowingAnnotation.throwing())) {
springAdvice.setThrowingName(afterThrowingAnnotation.throwing());
}
break;
case AtAround:
springAdvice = new AspectJAroundAdvice(candidateAdviceMethod, ajexp, aif);
break;
case AtPointcut:
if (logger.isDebugEnabled()) {
logger.debug("Processing pointcut '" + candidateAdviceMethod.getName() + "'");
}
return null;
default:
throw new UnsupportedOperationException(
"Unsupported advice type on method " + candidateAdviceMethod);
}
// Now to configure the advice...
springAdvice.setAspectName(aspectName);
springAdvice.setDeclarationOrder(declarationOrderInAspect);
String[] argNames = this.parameterNameDiscoverer.getParameterNames(candidateAdviceMethod);
if (argNames != null) {
springAdvice.setArgumentNamesFromStringArray(argNames);
}
springAdvice.calculateArgumentBindings();
return springAdvice;
}
/**
* Synthetic advisor that instantiates the aspect.
* Triggered by per-clause pointcut on non-singleton aspect.
* The advice has no effect.
*/
protected static class SyntheticInstantiationAdvisor extends DefaultPointcutAdvisor {
public SyntheticInstantiationAdvisor(final MetadataAwareAspectInstanceFactory aif) {
super(aif.getAspectMetadata().getPerClausePointcut(), new MethodBeforeAdvice() {
public void before(Method method, Object[] args, Object target) {
// Simply instantiate the aspect
aif.getAspectInstance();
}
});
}
}
}