When Spring AOP applies advice to your beans, it does so by resolving join points—specific points in the execution of your application, such as method calls—against pointcuts, which define where advice should run. Internally, Spring maintains a set of pointcut expressions, each associated with one or more pieces of advice. When a method is invoked on a proxied bean, Spring's proxy mechanism intercepts the call and checks whether the method matches any configured pointcuts. If a match is found, the corresponding advice is invoked.

The process unfolds in a precise sequence. First, the proxy intercepts the method invocation. It then evaluates each aspect's pointcut expression against the method's metadata (such as method name, parameters, or annotations). If the method matches a pointcut, Spring collects all applicable advice, orders them according to their type and precedence, and wraps the method execution in advice logic. For around advice, this means you can control whether, when, and how the original method is actually called. Other advice types (before, after, etc.) are woven into the call flow at their respective join points.

This mechanism allows you to modularize cross-cutting concerns, such as logging or transaction management, without altering your core business logic. The proxy acts as an intelligent gatekeeper, ensuring that advice is applied only when pointcut conditions are met.