Aspect-Oriented Programming (AOP)
A typical JAVA application is developed with multiple layers, each layer having a different responsibility. But, in each of these layers, there are a few common aspects, that is, Logging, Security, Validation, Caching, etc. These common aspects are called cross-cutting concerns. Now, if we implement these cross-cutting concerns in each and every layer separately, the code becomes repetitive and difficult to maintain. Moreover, it does not make any sense to write a similar block of code in every layer. Here comes the concept of Aspect-Oriented Programming.
Aspect-Oriented Programming -
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Implement the cross-cutting concerns as an aspect
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Define pointcuts to indicate where the aspect has to be applied.
It ensures that the cross-cutting concerns are defined in one cohesive code component.
There are some important terms in Aspect-Oriented Programming -
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Join Point - A point during the execution of a program/method.
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Advice - Action taken by an aspect at a particular join point. Different types of advice include "around," "before" and "after" advice.
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Pointcut - A predicate that matches join points. Advice is associated with a pointcut expression and runs at any join point matched by the pointcut
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The advice and pointcut in the above code are-
Advice - “@After”, @Before
Pointcut - "execution(public * getEventBookingById(String,..))" + "|| execution(public * getUserById(java.util.UUID,..))", "execution(public * getUserById(java.util.UUID,..))", etc.