Defining pointcuts

As mentioned before, pointcuts are used to define a point where advice would be applied. So pointcut is one of the most important elements of an aspect in the application. Let's understand how to define pointcuts. In Spring AOP, we can use expression language to define the pointcuts. Spring AOP uses AspectJ's pointcut expression language for selecting where to apply advice. Spring AOP supports a subset of the pointcut designators available in AspectJ because as you know, Spring AOP is proxy-based and some designators do not support proxy-based AOP. Let's see following table has Spring AOP supported designators.

Spring supported AspectJ designators	Description
execution	It matches the join points by method executions, it is primary pointcut designator supported by Spring AOP.
within	It matches the join points by limit within certain types.
this	It limits matching to join points where the bean reference is an instance of the given type.
target	It limits matching to join points where...