🍃🎓 SPRING CERTIFICATION QUESTION: Which of the following AOP expressions match this requirement:

"any join point within the service package and a sub-package"?

Which of the following AOP expressions match this requirement: "any join point within the service package and a sub-package"?

* execution(* com.xyz.service.*.*(..))

* execution(* com.xyz.service..*.*(..))

* within(com.xyz.service.*)

* within(com.xyz.service..*)

#spring #certificationquestion #vcp

Answer: within(com.xyz.service..*)

execution(* com.xyz.service.*.*(..)) matches the execution of any method defined in the service package.

This expression only matches methods within immediate classes in the com.xyz.service package, but it does not match methods in sub-packages.

execution(* com.xyz.service..*.*(..)) matches the execution of any method defined in the service package or a sub-package

This expression matches method executions within the com.xyz.service package and any of its sub-packages.

However, this is a method execution pointcut, not just any join point.

within(com.xyz.service.*) matches any join point (method execution only in Spring AOP) within the service package.

This expression matches any join point (method execution, constructor execution, field access, etc.) within classes directly within the com.xyz.service package.

within(com.xyz.service..*) matches any join point (method execution only in Spring AOP) within the service package or a sub-package.

This expression matches any join point within classes within the com.xyz.service package and any of its sub-packages.

This is the correct expression that matches the requirement of any join point within the service package or a sub-package.

https://docs.spring.io/spring-framework/docs/2.0.x/reference/aop.html

Note that within(com.xyz.service.*) concerns only the com.xyz.service package, but the requirement asks for the service package or a sub package.

So this response is not suitable.

And remember the wildcards:

* matches once (return type, package, class, method name, argument)

.. matches zero or more (arguments or packages)