Question

I have two annotation @LookAtThisMethod and @LookAtThisParameter, if I have a pointcut around the methods with @LookAtThisMethod how could I extract the parameters of said method which are annotated with @LookAtThisParameter?

For example:

@Aspect
public class LookAdvisor {

    @Pointcut("@annotation(lookAtThisMethod)")
    public void lookAtThisMethodPointcut(LookAtThisMethod lookAtThisMethod){}

    @Around("lookAtThisMethodPointcut(lookAtThisMethod)")
    public void lookAtThisMethod(ProceedingJoinPoint joinPoint, LookAtThisMethod lookAtThisMethod) throws Throwable {
        for(Object argument : joinPoint.getArgs()) {
            //I can get the parameter values here
        }

        //I can get the method signature with:
        joinPoint.getSignature.toString();


        //How do I get which parameters  are annotated with @LookAtThisParameter?
    }

}

Answer 1

I modeled my solution around this other answer to a different but similar question.

MethodSignature signature = (MethodSignature) joinPoint.getSignature();
String methodName = signature.getMethod().getName();
Class<?>[] parameterTypes = signature.getMethod().getParameterTypes();
Annotation[][] annotations = joinPoint.getTarget().getClass().getMethod(methodName,parameterTypes).getParameterAnnotations();

The reason that I had to go through the target class was because the class that was annotated was an implementation of an interface and thusly signature.getMethod().getParameterAnnotations() returned null.