WebMvcConfigurer - VittorioDeMarzi/hero-beans GitHub Wiki

Purpose of WebMvcConfigurer Configuration Class

This configuration class customizes Spring MVC behavior for our application. It mainly serves two purposes:

  1. Registering application-specific interceptors
  2. Registering custom method argument resolvers

1. Interceptors (addInterceptors)

We register the JwtAuthInterceptor to handle authentication for specific API endpoints. This interceptor is responsible for:

  • Extracting and validating the JWT token from incoming requests.
  • Setting the authenticated user’s data in the request attributes so that downstream components can access it.

We apply it only to the relevant paths:

  • /api/user/wishes/** β†’ Protects user wish-related endpoints.
  • /api/admin/** and /api/admin/stats/** β†’ Protects administrative endpoints.
  • /api/payments/** β†’ Secures payment-related operations.

Reason: By specifying path patterns, we avoid running the interceptor on public endpoints, improving performance and keeping authentication checks targeted.

2. Argument Resolvers (addArgumentResolvers)

We register two custom HandlerMethodArgumentResolver implementations:

  • LoginMemberArgumentResolver: Automatically injects the currently logged-in member into controller method parameters without requiring manual lookups.

  • AdminOnlyResolver: Resolves and validates that the current user is an admin before allowing the method to be executed.

Reason: Argument resolvers keep controller code cleaner by moving authentication and authorization logic out of controller methods, following the Separation of Concerns principle.

Why This Approach?

  • Centralized Configuration β†’ All authentication and argument-binding logic is declared in one place.
  • Reusability β†’ Interceptors and resolvers can be reused across multiple controllers without code duplication.
  • Security β†’ Ensures that authentication and role-based access control are consistently applied.
  • Maintainability β†’ If we need to adjust authentication rules or add new resolvers, we do it in one place.