org.springframework.web.servlet

Interface AsyncHandlerInterceptor

All Superinterfaces:

HandlerInterceptor

All Known Implementing Classes:

ConversionServiceExposingInterceptor, HandlerInterceptorAdapter, LocaleChangeInterceptor, ThemeChangeInterceptor, UserRoleAuthorizationInterceptor, WebRequestHandlerInterceptorAdapter

public interface AsyncHandlerInterceptor
extends HandlerInterceptor

Extends HandlerInterceptor with a callback method invoked during asynchronous request handling.

When a handler starts asynchronous request handling, the DispatcherServlet exits without invoking postHandle and afterCompletion, as it normally does, since the results of request handling (e.g. ModelAndView) will. be produced concurrently in another thread. In such scenarios, afterConcurrentHandlingStarted(HttpServletRequest, HttpServletResponse, Object) is invoked instead allowing implementations to perform tasks such as cleaning up thread bound attributes.

When asynchronous handling completes, the request is dispatched to the container for further processing. At this stage the DispatcherServlet invokes preHandle, postHandle and afterCompletion as usual.

Since:

3.2

Author:

Rossen Stoyanchev

See Also:

WebAsyncManager, CallableProcessingInterceptor, DeferredResultProcessingInterceptor

Method Summary

Methods

Modifier and Type	Method and Description
void	afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler) Called instead of postHandle and afterCompletion, when the a handler is being executed concurrently.

Methods inherited from interface org.springframework.web.servlet.HandlerInterceptor

afterCompletion, postHandle, preHandle

Method Detail

afterConcurrentHandlingStarted

void afterConcurrentHandlingStarted(HttpServletRequest request,
                                  HttpServletResponse response,
                                  Object handler)
                                    throws Exception

Called instead of postHandle and afterCompletion, when the a handler is being executed concurrently. Implementations may use the provided request and response but should avoid modifying them in ways that would conflict with the concurrent execution of the handler. A typical use of this method would be to clean thread local variables.

Parameters:

request - the current request

response - the current response

handler - handler (or HandlerMethod) that started async execution, for type and/or instance examination

Throws:

Exception - in case of errors