Can someone explain AOP concepts for dummies: join point, point cut, weaving etc.
For example: Aspect: a modularization of a concern that cuts across multiple classes. What does that mean?
Software Engineering Stack Exchange is a question and answer site for professionals, academics, and students working within the systems development life cycle. It only takes a minute to sign up.Sign up to join this community
Think of a concern as a functionality group e.g. logging, auditing, security
These functionalities are ever present in most code, but they don't really live in our animal->dog classes - they are functionality that should live in many classes - they are cross cutting concerns.
A Joinpoint is a place in the code where the aspect code is actually ran.
A pointcut is how to say what code runs at the jointpoint.
Weaving - is when the compiler/system takes your normal code and includes all the AOP code so that it triggers the correct code etc - can think of this as an extra pre-compile step.
A simple understandable example is:
Please be aware that terminology differs slightly between different implementations and AOP frameworks.
Each definition builds on the previous ones.
Something that bothers you (concern) everywhere (cross-cutting) across you application. e.g logging or security
A chunk of code that is automatically added before, after, or both (around) your existing code
Application code | | | | \|/ | JoinPoint ----------->("before" aspect, on the way in) // just before your intercepted application code Pointcut start--------> public String myMethod(params ...) //your application code Pointcut finish--------> return (foo) JoinPoint ----------->("after" aspect, on the way out) // just after your intercepted application code | \|/ | | | Application code
A place in code execution where part of the aspect execute.
The point where your aspect "joins" the pointcut. At a "before" joinPoint you will have access to parameters, at "after" joinPoint you will have access to the return value. If an exception is thrown, you may need a "try-catch-finally" to handle or re-throw it.
The process of adding aspects around a pointcut