Question

我有2个自定义注释：

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
public @interface FlowPoint {
    public enum PointInFlow {
        START, END
    }
    PointInFlow pointInFlow();
}

和：

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
public @interface ScopeAnnotation {
    public enum Category {
        BUSINESS, DETECTION, INTERNAL_FUNC, THRESHOLD
    }
    Category category() default Category.DETECTION;
}

在我的代码中，我用PointInFlow.START注释了一个方法，并用Category.DETECTION和Category.BUSINESS注释了其他方法

我的观点是：

@Pointcut("execution(* *(..)) && @annotation(flowPoint) && if()")
public static boolean executeStartMethod(<annotationPackage>.FlowPoint flowPoint) {
        return flowPoint.pointInFlow() == FlowPoint.PointInFlow.START;}

@Before("executeStartMethod(flowPoint)")
public void beforeStartMethod(<annotationPackage>.FlowPoint flowPoint, JoinPoint jp) {
        logger.infoBefore(jp, flowPoint.pointInFlow());}

@After("executeStartMethod(flowPoint)")
public void afterStartMethod(<annotationPackage>.annotation.FlowPoint flowPoint, JoinPoint jp) {
        logger.infoAfter(jp);}


@Pointcut("execution(* *(..)) && @annotation(scopeAnnotation) && if()")
public static boolean executeDetectionMethod(<annotationPackage>.ScopeAnnotation scopeAnnotation) {
        return scopeAnnotation.category() == ScopeAnnotation.Category.DETECTION;}

@Before("executeDetectionMethod(scopeAnnotation)")
public void beforeDetectionMethod(<annotationPackage>.ScopeAnnotation scopeAnnotation, JoinPoint jp) {
        logger.infoBefore(jp, scopeAnnotation.category());}

@After("executeDetectionMethod(scopeAnnotation)")
public void afterDetectionMethod(<annotationPackage>.ScopeAnnotation scopeAnnotation, JoinPoint jp) {
        logger.infoAfter(jp);}


@Pointcut("execution(* *(..)) && @annotation(scopeAnnotation) && if()")
public static boolean executeBusinessMethod(<annotationPackage>.ScopeAnnotation scopeAnnotation) {
        return scopeAnnotation.category() == ScopeAnnotation.Category.BUSINESS;}

@Before("executeBusinessMethod(scopeAnnotation)")
public void beforeBusinessMethod(<annotationPackage>.ScopeAnnotation scopeAnnotation, JoinPoint jp) {
        logger.infoBefore(jp, scopeAnnotation.category());}

@After("executeBusinessMethod(scopeAnnotation)")
public void afterBusinessMethod(<annotationPackage>.annotation.ScopeAnnotation scopeAnnotation, JoinPoint jp) {
        logger.infoAfter(jp);}

问题是“检测”和“业务”分别工作（（当我注释掉检测或业务切入点定义之一时）。）但并非如上所述。

提前感谢您的帮助

Answer 1

您应该看到以下AspectJ编译错误：

circular advice precedence:
  can't determine precedence between two or more pieces of advice that apply to the same join point:
  method-execution(void de.scrum_master.app.Application.doEight())

作为解决方法，您可以执行以下操作：

@Pointcut("execution(* *(..)) && @annotation(scopeAnnotation) && if()")
public static boolean executeDetectionOrBusinessMethod(ScopeAnnotation scopeAnnotation) {
  return
    scopeAnnotation.category() == ScopeAnnotation.Category.DETECTION ||
    scopeAnnotation.category() == ScopeAnnotation.Category.BUSINESS;
}

@Before("executeDetectionOrBusinessMethod(scopeAnnotation)")
public void beforeDetectionOrBusinessMethod(ScopeAnnotation scopeAnnotation, JoinPoint jp) {
  infoBefore(jp, scopeAnnotation.category());
}

@After("executeDetectionOrBusinessMethod(scopeAnnotation)")
public void afterDetectionOrBusinessMethod(ScopeAnnotation scopeAnnotation, JoinPoint jp) {
  infoAfter(jp);
}

或者，如果您坚持将两个注释值的切入点和建议分开，只需在周围使用建议而不是之前/之后：

@Pointcut("execution(* *(..)) && @annotation(scopeAnnotation) && if()")
public static boolean executeDetectionMethod(ScopeAnnotation scopeAnnotation) {
  return scopeAnnotation.category() == ScopeAnnotation.Category.DETECTION;
}

@Around("executeDetectionMethod(scopeAnnotation)")
public Object aroundDetectionMethod(ScopeAnnotation scopeAnnotation, ProceedingJoinPoint jp) throws Throwable {
  infoBefore(jp, scopeAnnotation.category());
  try {
    return jp.proceed();
  } finally {
    infoAfter(jp);
  }
}

@Pointcut("execution(* *(..)) && @annotation(scopeAnnotation) && if()")
public static boolean executeBusinessMethod(ScopeAnnotation scopeAnnotation) {
  return scopeAnnotation.category() == ScopeAnnotation.Category.BUSINESS;
}

@Around("executeBusinessMethod(scopeAnnotation)")
public Object aroundBusinessMethod(ScopeAnnotation scopeAnnotation, ProceedingJoinPoint jp) throws Throwable {
  infoBefore(jp, scopeAnnotation.category());
  try {
    return jp.proceed();
  } finally {
    infoAfter(jp);
  }
}

Answer 2

不确定如何解决您提出的问题，但是无论如何我还是建议进行重构。

您实际上对3个不同的注释执行了相同的操作，因此我将把不同的分支与一个调度程序合并为一个分支，并且可能会使用@Around的建议，如@kriegaex所建议的。

我唯一想改变他的答案的方法是将两个@Around通知的相同正文提取到一个通用方法。

AspectJ-基于注释功能的切入点建议

2 个答案: