AOP

Aspect Oriented Programming

• Aspect-oriented Programming (AOP) complements Object-oriented Programming (OOP) by providing another way of thinking about program structure.
• The key unit of modularity in OOP is the class, whereas in AOP the unit of modularity is the aspect.
• AOP complements Spring IoC to provide a very capable middleware solution.
• https://docs.spring.io/spring-framework/reference/core/aop.html
• Java Brains - Spring AOP: https://www.youtube.com/watch?v=QdyLsX0nG30&list=PLE37064DE302862F8

Cross Cutting Concerns

• Things which are not part of your problem but still are required, maybe because of security, infrastructure etc.
• They are required in a lot of objects but are not really part of your business logic
• Examples:
  • Logging
  • Transactions
  • Security

Steps in AOP

• Identify cross cutting concerns and write Aspects
• Configure where the aspects apply
  • example: enable logging for some methods

AOP Annotations

• @Aspect (Class Level)
• Advice (Method Level):
  • @Before
  • @After
  • @Around

How AOP works

• It uses Proxy design pattern internally

What is AspectJ??