Package org.apache.struts2.interceptor

Interface WithLazyParams

All Known Implementing Classes:
ActionFileUploadInterceptor
public interface WithLazyParams
Interceptors marked with this interface support dynamic parameter evaluation at action invocation time. Parameters are set during interceptor creation (factory time), then re-evaluated during each action invocation to resolve expressions like ${someValue}.

This enables both:

  • Static configuration in interceptor stacks (e.g., allowedTypes="image/png,image/jpeg")
  • Dynamic expressions evaluated per-request (e.g., maximumSize="${maxUploadSize}")

The Interceptor.init() method is called after initial parameter setting, so interceptors can rely on configured values during initialization. Expression parameters (containing ${...}) are re-evaluated at invocation time via WithLazyParams.LazyParamInjector.

Since:
2.5.9