Aspect-Oriented Programming (AOP) is a programming paradigm that allows you to separate cross-cutting concerns from your main business logic.
Key Concepts:
Cross-cutting concerns - functionality that spans multiple parts of an application:
- Logging
- Security
- Transaction management
- Caching
- Error handling
Core AOP Terms:
- Aspect - A module that encapsulates cross-cutting concerns
- Join Point - A point in program execution (method calls, field access)
- Pointcut - Expression that selects join points where advice should be applied
- Advice - Code that runs at a join point (before, after, around)
- Weaving - Process of applying aspects to target objects
Spring AOP Example:
@Aspect
@Component
public class LoggingAspect {@Before("execution(* com.example.service.*.*(..))")public void logBefore(JoinPoint joinPoint) {System.out.println("Executing: " + joinPoint.getSignature().getName());}@After("execution(* com.example.service.*.*(..))")public void logAfter(JoinPoint joinPoint) {System.out.println("Completed: " + joinPoint.getSignature().getName());}
}Benefits:
- Separation of concerns - Keep business logic clean
- Code reusability - Apply same aspect to multiple classes
- Maintainability - Centralize cross-cutting logic
- Modularity - Easy to add/remove aspects