Spring Boot Interceptors vs .NET Action Filters

Spring Boot Interceptors and .NET Action Filters are highly equivalent in terms of purpose, design, and behavior. Both allow you to run code before or after an incoming request hits your core business logic (your controllers) without cluttering the controllers themselves.

There is a slight misconception about Spring Boot being entirely a backend framework, which we'll clear up below, but your architectural comparison is spot-on.

Key Takeaway
If you are familiar with ASP.NET Core Action Filters, you can think of a Spring MVC Interceptor as almost the same concept implemented in the Spring ecosystem.

How They Match Up (Concept by Concept)

If you are coming from .NET to Spring Boot, here is how the concepts map directly to one another:

Feature / Concept	.NET (ASP.NET Core)	Spring Boot (Spring MVC)
The Component	ActionFilterAttribute or IActionFilter	HandlerInterceptor
Before the Controller Executes	OnActionExecuting()	preHandle()
After the Controller Executes (Before View)	OnActionExecuted()	postHandle()
After Everything is Done (Cleanup / Exceptions)	OnResultExecuted() or Middleware cleanup	afterCompletion()
Registration	Registered globally, via Controllers, or Dependency Injection	Registered via a WebMvcConfigurer configuration class

Typical Use Cases

Both frameworks commonly use Interceptors / Action Filters for the following cross-cutting concerns:

• Logging and Metrics — Tracking request execution times, request tracing, and performance metrics.
• Authentication & Authorization — Verifying tokens, sessions, permissions, and access rights before the controller executes.
• Request Manipulation — Enriching the request context with additional metadata such as correlation IDs, tenant information, or tracing identifiers.
• Auditing — Capturing user activity and recording security-relevant operations.
• Monitoring — Integrating with observability platforms such as Prometheus, Grafana, Application Insights, or OpenTelemetry.

The Subtle Difference: Interceptors vs Filters

In both ecosystems, developers sometimes confuse Interceptors with Filters. Understanding where each component sits in the request processing pipeline is important.

Important:
Filters operate closer to the raw HTTP layer, while Interceptors / Action Filters operate closer to the MVC framework layer where controller metadata is available.

In .NET

• Middleware handles raw HTTP requests very early in the request pipeline.
• Action Filters execute later inside the MVC framework.
• Action Filters have access to controller metadata, action parameters, model binding information, and execution context.

In Spring Boot

• Servlet Filters execute early and process raw HTTP requests and responses.
• Handler Interceptors execute later after Spring MVC maps the request to a controller.
• Interceptors are aware of the selected controller handler and MVC execution context.

Pipeline Comparison

ASP.NET Core

HTTP Request
    ↓
Middleware
    ↓
Action Filter
    ↓
Controller Action
    ↓
Response

Spring Boot

HTTP Request
    ↓
Servlet Filter
    ↓
Handler Interceptor
    ↓
Controller
    ↓
Response

Final Conclusion

Spring MVC Interceptor ≈ ASP.NET Core Action Filter

Both are framework-aware request interception mechanisms that allow developers to execute logic:

• Before controller execution
• After controller execution
• After request completion
• Without polluting business logic

The primary difference is not in capability but in terminology and framework implementation details.