Aspect Oriented Programming

• Typically in Spring projects we are using layered approach to build applications.
  • Web Layer
  • Business Layer
  • Data Layer
• Although each layer has different responsibilities, There are few common aspects that apply to all layers
• Such as security, logging, performance etc. This common aspects are called Cross Cutting Concerns
• Aspect Oriented Programming are implementing Cross Cutting Concerns
• We can implement AOP with 2 popular AOP Frameworks:
  • Spring AOP: This framework only works with Spring Beans and it is not a complete solution
  • AspectJ: This framework is complete AOP solution
• AOP Terminology:
  • Advice: The answer that what code to execute. Like Logging, Authentication etc.
  • Pointcut: Annotation that identifies method calls to be intercepted. If you are looking for example, you can check out my codes in LoggingAspect.java
  • Aspect: Framework that implements AOP
• Annotations:
  • @Before: Do something before method is called
  • @After: Do something after method is executed irrespective of whether:
    • Method executes successfully
    • Method throws an exception
  • @AfterRunning: Do something only when a method executes successfully
  • @AfterThrowing: Do something only when a method throws an exception