这篇文章主要介绍“Springframework中的ReflectiveAspectJAdvisorFactory有什么作用”，在日常操作中，相信很多人在Springframework中的ReflectiveAspectJAdvisorFactory有什么作用问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”Springframework中的ReflectiveAspectJAdvisorFactory有什么作用”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
Spring版本是5.0.4.release.
ReflectiveAspectJAdvisorFactory这个类，个人觉得是Spring aop的一个核心类。如下List-1所示，ReflectiveAspectJAdvisorFactory间接实现了AspectJAdvisorFactory。
List-1
计算
安全
数据库
网络和加速
企业服务
public interface AspectJAdvisorFactory {
boolean isAspect(Class<?> clazz);
void validate(Class<?> aspectClass) throws AopConfigException;
List<Advisor> getAdvisors(MetadataAwareAspectInstanceFactory aspectInstanceFactory);
Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aspectInstanceFactory,
int declarationOrder, String aspectName);
Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut expressionPointcut,
MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName);
}List-1中的isAspect方法判断类上是否有Aspect注解，BeanFactoryAspectJAdvisorsBuilder就用这个方法判断一个类上是有Aspect注解。
有必要来看下AbstractAspectJAdvisorFactory这个类，因为ReflectiveAspectJAdvisorFactory继承了它。如下List-2所示，isAspect方法判断类上是有Aspect注解。
List-2
public abstract class AbstractAspectJAdvisorFactory implements AspectJAdvisorFactory {
private static final String AJC_MAGIC = "ajc$";
private static final Class<?>[] ASPECTJ_ANNOTATION_CLASSES = new Class<?>[] {
Pointcut.class, Around.class, Before.class, After.class, AfterReturning.class, AfterThrowing.class};
protected final Log logger = LogFactory.getLog(getClass());
protected final ParameterNameDiscoverer parameterNameDiscoverer = new AspectJAnnotationParameterNameDiscoverer();
@Override
public boolean isAspect(Class<?> clazz) {
return (hasAspectAnnotation(clazz) && !compiledByAjc(clazz));
}
private boolean hasAspectAnnotation(Class<?> clazz) {
return (AnnotationUtils.findAnnotation(clazz, Aspect.class) != null);
}
...如下List-3所示，这个类还有个工具方法，查看方法上面是否有Pointcut.class, Around.class, Before.class, After.class, AfterReturning.class, AfterThrowing.class注解，如果找到一个，则封装为AspectJAnnotation返回。
List-3
@Nullable
protected static AspectJAnnotation<?> findAspectJAnnotationOnMethod(Method method) {
for (Class<?> clazz : ASPECTJ_ANNOTATION_CLASSES) {
AspectJAnnotation<?> foundAnnotation = findAnnotation(method, (Class<Annotation>) clazz);
if (foundAnnotation != null) {
return foundAnnotation;
}
}
return null;
}
@Nullable
private static <A extends Annotation> AspectJAnnotation<A> findAnnotation(Method method, Class<A> toLookFor) {
A result = AnnotationUtils.findAnnotation(method, toLookFor);
if (result != null) {
return new AspectJAnnotation<>(result);
}
else {
return null;
}
}ReflectiveAspectJAdvisorFactory的getAdvice方法会根据方法上的注解，创建对应的Advice，如下List-4所示
List-4
public Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut expressionPointcut,
MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {
AbstractAspectJAdvice springAdvice;
...
switch (aspectJAnnotation.getAnnotationType()) {
case AtPointcut:
if (logger.isDebugEnabled()) {
logger.debug("Processing pointcut '" + candidateAdviceMethod.getName() + "'");
}
return null;
case AtAround:
springAdvice = new AspectJAroundAdvice(
candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
break;
case AtBefore:
springAdvice = new AspectJMethodBeforeAdvice(
candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
break;
case AtAfter:
springAdvice = new AspectJAfterAdvice(
candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
break;
case AtAfterReturning:
springAdvice = new AspectJAfterReturningAdvice(
candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
AfterReturning afterReturningAnnotation = (AfterReturning) aspectJAnnotation.getAnnotation();
if (StringUtils.hasText(afterReturningAnnotation.returning())) {
springAdvice.setReturningName(afterReturningAnnotation.returning());
}
break;
case AtAfterThrowing:
springAdvice = new AspectJAfterThrowingAdvice(
candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
AfterThrowing afterThrowingAnnotation = (AfterThrowing) aspectJAnnotation.getAnnotation();
if (StringUtils.hasText(afterThrowingAnnotation.throwing())) {
springAdvice.setThrowingName(afterThrowingAnnotation.throwing());
}
break;
default:
throw new UnsupportedOperationException(
"Unsupported advice type on method: " + candidateAdviceMethod);
}
...到此，关于“Springframework中的ReflectiveAspectJAdvisorFactory有什么作用”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注亿速云网站，小编会继续努力为大家带来更多实用的文章！
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原文链接：https://my.oschina.net/u/2518341/blog/3073109
