Package org.apache.struts2.interceptor

Interface WithLazyParams<P extends InterceptorParams>

All Known Implementing Classes:

ActionFileUploadInterceptor

public interface WithLazyParams<P extends InterceptorParams>

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 and written into a fresh InterceptorParams holder, never back onto the interceptor, which is shared across requests and stays untouched after Interceptor.init().

Since:

2.5.9

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	WithLazyParams.LazyParamInjector

Method Summary

Modifier and Type	Method	Description
String	intercept(ActionInvocation invocation, P lazyParams)	Invoked in place of Interceptor.intercept(ActionInvocation) when lazy params apply.
P	newLazyParams()

Method Details

newLazyParams

P newLazyParams()

Returns:

a fresh holder for one invocation, seeded from the configured values

Since:

7.3.0

intercept

String intercept(ActionInvocation invocation,
 P lazyParams)
          throws Exception

Invoked in place of Interceptor.intercept(ActionInvocation) when lazy params apply.

Parameters:

lazyParams - params resolved for this invocation only

Throws:

Exception

Since:

7.3.0