Spring AOP AfterThrowing vs. Around Advice

java spring-aop
whiskerz picture whiskerz · Mar 23, 2010 · Viewed 28.4k times · Source

when trying to implement an Aspect, that is responsible for catching and logging a certain type of error, I initially thought this would be possible using the AfterThrowing advice. However it seems that his advice doesn't catch the exception, but just provides an additional entry point to do something with the exception.

The only advice which would also catch the exception in question would then be an AroundAdvice - either that or I did something wrong.

Can anyone assert that indeed if I want to catch the exception I have to use an AroundAdvice? The configuration I used follows: 

@Pointcut("execution(* test.simple.OtherService.print*(..))")
public void printOperation() {}

@AfterThrowing(pointcut="printOperation()", throwing="exception")
public void logException(Throwable exception) {
  System.out.println(exception.getMessage());
}

@Around("printOperation()")
public void swallowException(ProceedingJoinPoint pjp) throws Throwable {
  try {
    pjp.proceed();
  } catch (Throwable exception) {
    System.out.println(exception.getMessage());
  }
}

Note that in this example I caught all Exceptions, because it just is an example. I know its bad practice to just swallow all exceptions, but for my current use case I want one special type of exception to be just logged while avoiding duplicate logging logic.

Answer

Shane Bell picture Shane Bell · Mar 24, 2010

The Spring reference doc says:

"After throwing advice runs when a matched method execution exits by throwing an exception"

By then it's too late to catch the exception as it has already been thrown and the method has exited. The approach you've taken with the @Around advice is the only way to actually catch the exception and deal with it before the method exits.

Related questions

Spring - @Transactional - What happens in background?

I want to know what actually happens when you annotate a method with @Transactional? Of course, I know that Spring will wrap that method in a Transaction. But, I have the following doubts: I heard that Spring creates a proxy …

Read More
@AspectJ pointcut for all methods of a class with specific annotation

I want to monitor all public methods of all Classes with specified annotation (say @Monitor) (note: Annotation is at class level). What could be a possible pointcut for this? Note: I am using @AspectJ style Spring AOP.

Read More
Spring AOP vs AspectJ

I am under the impression that Spring AOP is best used for application specific tasks such as security, logging, transactions, etc. as it uses custom Java5 annotations as a framework. However, AspectJ seems to be more friendly design-patterns wise. Can …

Read More