Spring AOP

This keynote provides a short introduction for using Spring AOP to modularize your cross cutting concerns and keep your code clean.

1. Spring AOP
Aspect-Oriented Programming with Spring

2. Jeroen Rosenberg, Java Developer
[email protected]

3. Table of Contents

4. Table of Contents
‣Why Aspect-Oriented Programming?

5. Table of Contents
‣Why Aspect-Oriented Programming?
‣Basic AOP Concepts

6. Table of Contents
‣Why Aspect-Oriented Programming?
‣Basic AOP Concepts
‣Getting Started with Spring AOP

7. Table of Contents
‣Why Aspect-Oriented Programming?
‣Basic AOP Concepts
‣Getting Started with Spring AOP
‣Benefits and Drawbacks

8. Table of Contents
‣Why Aspect-Oriented Programming?
‣Basic AOP Concepts
‣Getting Started with Spring AOP
‣Benefits and Drawbacks
‣When to Use Spring AOP?

9. Aspect-Oriented Programming (AOP)
enables modularization of cross-
cutting concerns

10. Cross-cutting Concerns

11. Cross-cutting Concerns
‣Logging
‣Validation
‣Transaction
Management
‣Security
‣Caching

12. Code Tangling

13. Coupling of different concerns
Code Tangling

14. Code Scattering

15. Code Scattering
Same concern spread across
modules

16. The encouraged approach for implementing cross-cutting concerns

17. The encouraged approach for implementing cross-cutting concerns

18. The encouraged approach for implementing cross-cutting concerns
1. Solve core problem

19. The encouraged approach for implementing cross-cutting concerns
1. Solve core problem

20. The encouraged approach for implementing cross-cutting concerns
1. Solve core problem
2. Write aspects

21. The encouraged approach for implementing cross-cutting concerns
1. Solve core problem
2. Write aspects

22. The encouraged approach for implementing cross-cutting concerns
1. Solve core problem
2. Write aspects
3. Weave at runtime

23. AOP Terminology

24. ‣An aspect is a module that encapsulates advice and pointcuts
AOP Terminology

25. ‣An aspect is a module that encapsulates advice and pointcuts
‣An advice is code to be executed at a join point selected by a pointcut
AOP Terminology

26. ‣An aspect is a module that encapsulates advice and pointcuts
‣An advice is code to be executed at a join point selected by a pointcut
‣A pointcut is an expression that selects one or more join points
AOP Terminology

27. ‣An aspect is a module that encapsulates advice and pointcuts
‣An advice is code to be executed at a join point selected by a pointcut
‣A pointcut is an expression that selects one or more join points
‣A join point is a point in the execution of a program
AOP Terminology

28. Spring AOP
Java-based AOP framework

29. Spring uses dynamic proxying for aspect weaving

30. Calls on the object reference will be calls on the proxy and the proxy
delegates to all of the relevant advices

31. Calls on the object reference will be calls on the proxy and the proxy
delegates to all of the relevant advices
Regular method invocation

32. Calls on the object reference will be calls on the proxy and the proxy
delegates to all of the relevant advices
Regular method invocation Proxied method invocation

33. Spring offers 3 ways to accomplish AOP support
Annotation based
with AspectJ
Schema based
with AspectJ
Schema based
without AspectJ
Very easy to
configure
Bloated
configuration
Easy to configure
Horizontal class
relationships at
code level
Horizontal class
relationships at
deployment level
Horizontal class
relationships at
deployment level
Degrades
portability
Enables portabilityEnables portability

34. Schema based aspect
configuration without AspectJ
Configuration

35. Sample XML configuration

36. Demo

37. No special compiler required to allow
per-object interception
Benefits

38. Drawbacks
Lower performance

39. AOP Suitability
Concern
Logging VVVV V
Validation VVVVVVV?
Transaction ManagementVVVVVVVV
Security VVV? V??
Caching VVV??V?V
CrosscuttingAspectizabilityObliviousnessCode reductionReliabilityModularityEvolvabilityCost-effectiveness

40. Summary
Modularization of
cross cutting concerns
Auto-proxying for
aspect weaving
Schema based
aspect configuration