Spring AOPソースの解読2-カットと強化の取得
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前言
前の文章では代理処理の入口を紹介しました.この章では代理処理の流れの一つを紹介します.
本文
まず、 findCandCadidateAdvisors:適切なAdvisorを検索します. findAdvisors ThatCanply:AdvisorがBeanに使われているかどうかを見てください.(AdvisorのPointCutによって判断します.)
findCandCanddidateAdvisors方法については、AsppectJの関連する処理を分析していますので、この方法はAnnotationAwareAspect AutoxyCreator類において実現されたものです.
findCandCadidateAdvisorsは名前のマッチングを通して、適当なAdvisorを見つけました.findAdvisors ThaCanplyの方法を見に来ました.この方法はPointCutによってターゲットクラスが代理対象の条件に合致しているかどうかを確認し、該当する場合はAdvisorを集合に追加し、最後に集合に戻ります.
前の文章では代理処理の入口を紹介しました.この章では代理処理の流れの一つを紹介します.
本文
まず、
getAdvicesAndAdvisorsForBean方法の内容を見て、この方法の実現はサブクラスAbstractAdvisorAutoProxyCreatorにおいて行われる.この方法の中の主なロジックはfindEligible Advisors方法の中にあります.protected Object[] getAdvicesAndAdvisorsForBean(Class> beanClass, String beanName, TargetSource targetSource) {
List advisors = findEligibleAdvisors(beanClass, beanName);
if (advisors.isEmpty()) {
return DO_NOT_PROXY;
}
return advisors.toArray();
} protected List findEligibleAdvisors(Class> beanClass, String beanName) {
// Advisor
List candidateAdvisors = findCandidateAdvisors();
// Advisor Bean
List eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName);
extendAdvisors(eligibleAdvisors);
if (!eligibleAdvisors.isEmpty()) {
eligibleAdvisors = sortAdvisors(eligibleAdvisors);
}
return eligibleAdvisors;
} findCandCanddidateAdvisors方法については、AsppectJの関連する処理を分析していますので、この方法はAnnotationAwareAspect AutoxyCreator類において実現されたものです.
protected List findCandidateAdvisors() {
// Add all the Spring advisors found according to superclass rules.
// AOP XML 。
// AOP
List advisors = super.findCandidateAdvisors();
// Build Advisors for all AspectJ aspects in the bean factory.
// BeanFactory ， Spring （Advisor），
advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());
return advisors;
} public List buildAspectJAdvisors() {
List aspectNames = null;
synchronized (this) {
aspectNames = this.aspectBeanNames;
if (aspectNames == null) {
List advisors = new LinkedList();
aspectNames = new LinkedList();
// beanNamesForTypeIncludingAncestors bean，
// （ Object， ）
// DefaultListableBeanFactory#doGetBeanNamesForType
// Class#isAssignableFrom
String[] beanNames =
BeanFactoryUtils.beanNamesForTypeIncludingAncestors(this.beanFactory, Object.class, true, false);
for (String beanName : beanNames) {
// Bean ，
// ， 。
// DefaultAdvisorAutoProxyCreator ， ，!isUsePrefix() True， True
// AbstractBeanFactory#isTypeMatch
if (!isEligibleBean(beanName)) {
continue;
}
// We must be careful not to instantiate beans eagerly as in this
// case they would be cached by the Spring container but would not
// have been weaved
// bean
Class> beanType = this.beanFactory.getType(beanName);
if (beanType == null) {
continue;
}
// beanType Aspect
if (this.advisorFactory.isAspect(beanType)) {
aspectNames.add(beanName);
AspectMetadata amd = new AspectMetadata(beanType, beanName);
if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) {
MetadataAwareAspectInstanceFactory factory =
new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);
// Aspect ， Advisors。
List classAdvisors = this.advisorFactory.getAdvisors(factory);
if (this.beanFactory.isSingleton(beanName)) {
this.advisorsCache.put(beanName, classAdvisors);
}
else {
this.aspectFactoryCache.put(beanName, factory);
}
advisors.addAll(classAdvisors);
}
else {
// Per target or per this.
if (this.beanFactory.isSingleton(beanName)) {
throw new IllegalArgumentException("Bean with name '" + beanName +
"' is a singleton, but aspect instantiation model is not singleton");
}
MetadataAwareAspectInstanceFactory factory =
new PrototypeAspectInstanceFactory(this.beanFactory, beanName);
this.aspectFactoryCache.put(beanName, factory);
advisors.addAll(this.advisorFactory.getAdvisors(factory));
}
}
}
this.aspectBeanNames = aspectNames;
return advisors;
}
}
if (aspectNames.isEmpty()) {
return Collections.emptyList();
}
List advisors = new LinkedList();
for (String aspectName : aspectNames) {
List cachedAdvisors = this.advisorsCache.get(aspectName);
if (cachedAdvisors != null) {
advisors.addAll(cachedAdvisors);
}
else {
MetadataAwareAspectInstanceFactory factory = this.aspectFactoryCache.get(aspectName);
advisors.addAll(this.advisorFactory.getAdvisors(factory));
}
}
return advisors;
} public List 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 advisors = new LinkedList();
// aspectClass （ PointCut ）， Advisor， 。
// ( Advice， PointCut， Advisor)
for (Method method : getAdvisorMethods(aspectClass)) {
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;
} // ， ， ， Method ， ， 。
private List getAdvisorMethods(Class> aspectClass) {
final List methods = new LinkedList();
ReflectionUtils.doWithMethods(aspectClass, new ReflectionUtils.MethodCallback() {
@Override
public void doWith(Method method) throws IllegalArgumentException {
// Exclude pointcuts
if (AnnotationUtils.getAnnotation(method, Pointcut.class) == null) {
methods.add(method);
}
}
});
Collections.sort(methods, METHOD_COMPARATOR);
return methods;
} public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aif,
int declarationOrderInAspect, String aspectName) {
validate(aif.getAspectMetadata().getAspectClass());
// PointCut （ PointCut ）
// Method ， Method ，
// ， null； ， PointCut
// ：Before.class, Around.class, After.class, AfterReturning.class, AfterThrowing.class, Pointcut.class
AspectJExpressionPointcut ajexp =
getPointcut(candidateAdviceMethod, aif.getAspectMetadata().getAspectClass());
if (ajexp == null) {
return null;
}
// PointCut
return new InstantiationModelAwarePointcutAdvisorImpl(
this, ajexp, aif, candidateAdviceMethod, declarationOrderInAspect, aspectName);
}private AspectJExpressionPointcut getPointcut(Method candidateAdviceMethod, Class> candidateAspectClass) {
//
// Method ， ， null
// ：Before.class, Around.class, After.class, AfterReturning.class, AfterThrowing.class, Pointcut.class
AspectJAnnotation> aspectJAnnotation =
AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);
if (aspectJAnnotation == null) {
return null;
}
// AspectJExpressionPointcut
AspectJExpressionPointcut ajexp =
new AspectJExpressionPointcut(candidateAspectClass, new String[0], new Class>[0]);
// ：
// @Pointcut（"execution（* test.TestBean.*(..)）"）
ajexp.setExpression(aspectJAnnotation.getPointcutExpression());
return ajexp;
}protected static AspectJAnnotation> findAspectJAnnotationOnMethod(Method method) {
// ，
Class>[] classesToLookFor = new Class>[] {
Before.class, Around.class, After.class, AfterReturning.class, AfterThrowing.class, Pointcut.class};
for (Class> c : classesToLookFor) {
AspectJAnnotation> foundAnnotation = findAnnotation(method, (Class) c);
if (foundAnnotation != null) {
return foundAnnotation;
}
}
return null;
} // AspectJAnnotation
private static AsppectJAnnotationfindAnnotation（Method method、Class）tolook For){
A result=AnnotationUtils.findAnnotation；
if(result！=null){
return new Aspect JAnnotation（レスリング）
)
else{
return null
)
)getAdvisor方法の最後の行のコードは、接点情報に基づいてエンハンスを生成するreturn new InstantiationModelAwarePointcutAdvisorImpl(
this, ajexp, aif, candidateAdviceMethod, declarationOrderInAspect, aspectName)である.すべての拡張は、Advisorの実装クラスInstantiationModelAwarePointcutAdvisorImplによって統一的にカプセル化されている.public InstantiationModelAwarePointcutAdvisorImpl(AspectJAdvisorFactory af, AspectJExpressionPointcut ajexp,
MetadataAwareAspectInstanceFactory aif, Method method, int declarationOrderInAspect, String aspectName) {
this.declaredPointcut = ajexp;
this.method = method;
this.atAspectJAdvisorFactory = af;
this.aspectInstanceFactory = aif;
this.declarationOrder = declarationOrderInAspect;
this.aspectName = aspectName;
if (aif.getAspectMetadata().isLazilyInstantiated()) {
// Static part of the pointcut is a lazy type.
Pointcut preInstantiationPointcut =
Pointcuts.union(aif.getAspectMetadata().getPerClausePointcut(), this.declaredPointcut);
// Make it dynamic: must mutate from pre-instantiation to post-instantiation state.
// If it's not a dynamic pointcut, it may be optimized out
// by the Spring AOP infrastructure after the first evaluation.
this.pointcut = new PerTargetInstantiationModelPointcut(this.declaredPointcut, preInstantiationPointcut, aif);
this.lazy = true;
}
else {
// A singleton aspect.
// Advice
this.instantiatedAdvice = instantiateAdvice(this.declaredPointcut);
this.pointcut = declaredPointcut;
this.lazy = false;
}
}private Advice instantiateAdvice(AspectJExpressionPointcut pcut) {
return this.atAspectJAdvisorFactory.getAdvice(
this.method, pcut, this.aspectInstanceFactory, this.declarationOrder, this.aspectName);
}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);
}findCandCadidateAdvisorsは名前のマッチングを通して、適当なAdvisorを見つけました.findAdvisors ThaCanplyの方法を見に来ました.この方法はPointCutによってターゲットクラスが代理対象の条件に合致しているかどうかを確認し、該当する場合はAdvisorを集合に追加し、最後に集合に戻ります.
public static List findAdvisorsThatCanApply(List candidateAdvisors, Class> clazz) {
if (candidateAdvisors.isEmpty()) {
return candidateAdvisors;
}
List eligibleAdvisors = new LinkedList();
// IntroductionAdvisor Advisor，
for (Advisor candidate : candidateAdvisors) {
if (candidate instanceof IntroductionAdvisor && canApply(candidate, clazz)) {
eligibleAdvisors.add(candidate);
}
}
boolean hasIntroductions = !eligibleAdvisors.isEmpty();
// IntroductionAdvisor Advisor
for (Advisor candidate : candidateAdvisors) {
if (candidate instanceof IntroductionAdvisor) {
// already processed
continue;
}
//
if (canApply(candidate, clazz, hasIntroductions)) {
eligibleAdvisors.add(candidate);
}
}
return eligibleAdvisors;
}
// Advisor ， ， PointCut
public static boolean canApply(Advisor advisor, Class> targetClass, boolean hasIntroductions) {
if (advisor instanceof IntroductionAdvisor) {
return ((IntroductionAdvisor) advisor).getClassFilter().matches(targetClass);
}
// PointCut Advisor
else if (advisor instanceof PointcutAdvisor) {
PointcutAdvisor pca = (PointcutAdvisor) advisor;
return canApply(pca.getPointcut(), targetClass, hasIntroductions);
}
else {
// It doesn't have a pointcut so we assume it applies.
return true;
}
} // ， PointCut
public static boolean canApply(Pointcut pc, Class> targetClass, boolean hasIntroductions) {
Assert.notNull(pc, "Pointcut must not be null");
if (!pc.getClassFilter().matches(targetClass)) {
return false;
}
MethodMatcher methodMatcher = pc.getMethodMatcher();
IntroductionAwareMethodMatcher introductionAwareMethodMatcher = null;
if (methodMatcher instanceof IntroductionAwareMethodMatcher) {
introductionAwareMethodMatcher = (IntroductionAwareMethodMatcher) methodMatcher;
}
Set> classes = new LinkedHashSet>(ClassUtils.getAllInterfacesForClassAsSet(targetClass));
classes.add(targetClass);
for (Class> clazz : classes) {
Method[] methods = clazz.getMethods();
for (Method method : methods) {
if ((introductionAwareMethodMatcher != null &&
introductionAwareMethodMatcher.matches(method, targetClass, hasIntroductions)) ||
methodMatcher.matches(method, targetClass)) {
return true;
}
}
}
return false;
}