Re: [aspectj-users] Aspect instance per annotated method

["Alexander Kriegisch" <alexander@xxxxxxxxxxxxxx>]

Hi Jon.

I think there is no per-clause for distinct methods. I think your solution plus a Map, as you said, probably with keys generated from

    thisJoinPointStaticPart.getSignature().toLongString()

or similar should do. Sorry for not having any better ideas than you by yourself.

Regards
-- 
Alexander Kriegisch
http://scrum-master.de


Jon Mann schrieb am 22.07.2014 15:54:

> I have a simple aspect for caching the result of a method call.
> 
> An annotation is used to mark a method which should be cached:
> 
>     public @interface CacheResult { }
> 
> The aspect is implemented like this:
> 
>     @Aspect("perthis(targetMethod())")
>     public class CacheResultAspect {
> 
>         private Object result;
> 
>         @Pointcut("execution(@CacheResult * *.*())")
>         public void targetMethod() { }
> 
>         @Around("targetMethod()")
>         public Object aroundMethod(ProceedingJoinPoint thisJoinPoint) 
> throws Throwable {
>             if (result == null) {
>                 result = thisJoinPoint.proceed();
>             }
>             return result;
>         }
>     }
> 
> This works great for target classes with only one @CacheResult method.
> 
> But the problem is target classes which have multiple different 
> @CacheResult methods:
> 
>     class Target {
>         @CacheResult String method1() { return "method1"; }
>         @CacheResult String method2() { return "method2"; }
>     }
> 
>     Target target = new Target();
>     target.method1();   // Caches and returns "method1"
>     target.method2();   // Returns cached "method1" but should 
> separately cache and return "method2"
> 
> Currently, one instance of CacheResultAspect is created for each 
> instance of a target class, so the cache result is (incorrectly) shared 
> across all the @CacheResult methods of the target object.
> 
> Is there a way to make AspectJ create a separate instance of 
> CacheResultAspect for each @CacheResult method in a target object?
> 
> I could use a Map to work around this, but perhaps there is a better or 
> more performant solution?