public interface WebRequestInterceptor
WebRequest
abstraction.
This interface assumes MVC-style request processing: A handler gets executed, exposes a set of model objects, then a view gets rendered based on that model. Alternatively, a handler may also process the request completely, with no view to be rendered.
In an async processing scenario, the handler may be executed in a separate
thread while the main thread exits without rendering or invoking the
postHandle
and afterCompletion
callbacks. When concurrent
handler execution completes, the request is dispatched back in order to
proceed with rendering the model and all methods of this contract are invoked
again. For further options and comments see
org.springframework.web.context.request.async.AsyncWebRequestInterceptor
This interface is deliberately minimalistic to keep the dependencies of generic request interceptors as minimal as feasible.
ServletWebRequest
,
DispatcherServlet
,
AbstractHandlerMapping.setInterceptors(java.lang.Object...)
,
HandlerInterceptor
Modifier and Type | Method and Description |
---|---|
void |
afterCompletion(WebRequest request,
Exception ex)
Callback after completion of request processing, that is, after rendering
the view.
|
void |
postHandle(WebRequest request,
ModelMap model)
Intercept the execution of a request handler after its successful
invocation, right before view rendering (if any).
|
void |
preHandle(WebRequest request)
Intercept the execution of a request handler before its invocation.
|
void preHandle(WebRequest request) throws Exception
Allows for preparing context resources (such as a Hibernate Session) and expose them as request attributes or as thread-local objects.
request
- the current web requestException
- in case of errorsvoid postHandle(WebRequest request, @Nullable ModelMap model) throws Exception
Allows for modifying context resources after successful handler execution (for example, flushing a Hibernate Session).
request
- the current web requestmodel
- the map of model objects that will be exposed to the view
(may be null
). Can be used to analyze the exposed model
and/or to add further model attributes, if desired.Exception
- in case of errorsvoid afterCompletion(WebRequest request, @Nullable Exception ex) throws Exception
Note: Will only be called if this interceptor's preHandle
method has successfully completed!
request
- the current web requestex
- exception thrown on handler execution, if anyException
- in case of errors