Real World Example

Payment and banking apps (Paytm, PhonePe, net banking) must record who did what and when for every money movement. Instead of adding audit code to every method, ShopEase marks sensitive methods with @Audited and one aspect writes the audit row.

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Audited { String action(); }

@Aspect
@Component
@RequiredArgsConstructor
public class AuditAspect {
    private final AuditRepository auditRepository;

    @AfterReturning(pointcut = "@annotation(audited)", returning = "result")
    public void audit(JoinPoint jp, Audited audited, Object result) {
        String user = SecurityContextHolder.getContext().getAuthentication().getName();
        auditRepository.save(new AuditEntry(user, audited.action(),
                Arrays.toString(jp.getArgs()), String.valueOf(result), Instant.now()));
    }
}

@Service
public class RefundService {
    @Audited(action = "REFUND")
    @Transactional
    public RefundResponse refund(Long orderId, BigDecimal amount) { ... }
}

curl -X POST localhost:8080/api/admin/orders/1001/refund -H "Authorization: Bearer eyJ..." -H "Content-Type: application/json" -d '{"amount":499.00}'

HTTP/1.1 200 OK
{"orderId":1001,"refunded":499.00,"status":"REFUND_INITIATED"}

-- audit_entry table --
| user          | action | args           | result           | at                   |
| [email protected] | REFUND | [1001, 499.00] | REFUND_INITIATED | 2026-03-14T10:22:05Z |