接口 HandlerInterceptor
- 所有已知实现类:
HandlerInterceptorAdapter
,ParameterMappingInterceptor
,UserRoleAuthorizationInterceptor
,WebRequestHandlerInterceptorAdapter
public interface HandlerInterceptor
Workflow interface that allows for customized handler execution chains. Applications can register any number of existing or custom interceptors for certain groups of handlers, to add common pre-processing behavior without needing to modify each handler implementation.A
HandlerInterceptor
gets called before the appropriateHandlerAdapter
triggers the execution of the handler itself. This mechanism can be used for a large field of preprocessing aspects, e.g. for authorization checks, or common handler behavior like locale or theme changes. Its main purpose is to permit the factoring out of otherwise repetitive handler code.Typically an interceptor chain is defined per
HandlerMapping
bean, sharing its granularity. To be able to apply a certain interceptor chain to a group of handlers, one needs to map the desired handlers via oneHandlerMapping
bean. The interceptors themselves are defined as beans in the application context, referenced by the mapping bean definition via its"interceptors"
property (in XML: a <list> of <ref> elements).A
HandlerInterceptor
is basically similar to a ServletFilter
, but in contrast to the latter it allows custom pre-processing with the option to prohibit the execution of the handler itself, and custom post-processing.Filters
are more powerful; for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured inweb.xml
, aHandlerInterceptor
in the application context.As a basic guideline, fine-grained handler-related pre-processing tasks are candidates for
HandlerInterceptor
implementations, especially factored-out common handler code and authorization checks. On the other hand, aFilter
is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.Be aware that filters cannot be applied to portlet requests (they only operate on servlet requests), so for portlet requests interceptors are essential.
If we assume a "sunny day" request cycle (i.e. a request where nothing goes wrong and all is well), the workflow of a
HandlerInterceptor
will be as follows:Action Request:
DispatcherPortlet
maps the action request to a particular handler and assembles a handler execution chain consisting of the handler that is to be invoked and all of theHandlerInterceptor
instances that apply to the request.preHandleAction(..)
is called; if the invocation of this method returnstrue
then this workflow continues.- The target handler handles the action request (via
HandlerAdapter.handleAction(..)
). afterActionCompletion(..)
is called.
Render Request:
DispatcherPortlet
maps the render request to a particular handler and assembles a handler execution chain consisting of the handler that is to be invoked and all of theHandlerInterceptor
instances that apply to the request.preHandleRender(..)
is called; if the invocation of this method returnstrue
then this workflow continues.- The target handler handles the render request (via
HandlerAdapter.handleRender(..)
). postHandleRender(..)
is called.- If the
HandlerAdapter
returned aModelAndView
, thenDispatcherPortlet
renders the view accordingly. afterRenderCompletion(..)
is called.
- 从以下版本开始:
- 2.0
- 作者:
- Juergen Hoeller, John A. Lewis
- 另请参阅:
HandlerExecutionChain.getInterceptors()
,HandlerMapping
,AbstractHandlerMapping.setInterceptors(java.lang.Object[])
,HandlerExecutionChain
方法概要
所有方法 实例方法 抽象方法 修饰符和类型 方法 说明 void
afterActionCompletion(ActionRequest request, ActionResponse response, Object handler, Exception ex)
Callback after completion of request processing in the action phase, that is, after rendering the view.void
afterEventCompletion(EventRequest request, EventResponse response, Object handler, Exception ex)
Callback after completion of request processing in the action phase, that is, after rendering the view.void
afterRenderCompletion(RenderRequest request, RenderResponse response, Object handler, Exception ex)
Callback after completion of request processing, that is, after rendering the view.void
afterResourceCompletion(ResourceRequest request, ResourceResponse response, Object handler, Exception ex)
Callback after completion of request processing, that is, after rendering the view.void
postHandleRender(RenderRequest request, RenderResponse response, Object handler, ModelAndView modelAndView)
Intercept the execution of a handler in the render phase.void
postHandleResource(ResourceRequest request, ResourceResponse response, Object handler, ModelAndView modelAndView)
Intercept the execution of a handler in the render phase.boolean
preHandleAction(ActionRequest request, ActionResponse response, Object handler)
Intercept the execution of a handler in the action phase.boolean
preHandleEvent(EventRequest request, EventResponse response, Object handler)
Intercept the execution of a handler in the action phase.boolean
preHandleRender(RenderRequest request, RenderResponse response, Object handler)
Intercept the execution of a handler in the render phase.boolean
preHandleResource(ResourceRequest request, ResourceResponse response, Object handler)
Intercept the execution of a handler in the render phase.
方法详细资料
preHandleAction
boolean preHandleAction(ActionRequest request, ActionResponse response, Object handler) throws Exception
Intercept the execution of a handler in the action phase.Called after a HandlerMapping determines an appropriate handler object to handle an
ActionRequest
, but before said HandlerAdapter actually invokes the handler.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can decide to abort the execution chain, typically throwing an exception or writing a custom response.- 参数:
request
- current portlet action requestresponse
- current portlet action responsehandler
- chosen handler to execute, for type and/or instance evaluation- 返回:
true
if the execution chain should proceed with the next interceptor or the handler itself. Else,DispatcherPortlet
assumes that this interceptor has already dealt with the response itself- 抛出:
Exception
- in case of errors
afterActionCompletion
void afterActionCompletion(ActionRequest request, ActionResponse response, Object handler, Exception ex) throws Exception
Callback after completion of request processing in the action phase, that is, after rendering the view. Will be called on any outcome of handler execution, thus allowing for proper resource cleanup.Note: Will only be called if this interceptor's
preHandleAction(javax.portlet.ActionRequest, javax.portlet.ActionResponse, Object)
method has successfully completed and returnedtrue
!- 参数:
request
- current portlet action requestresponse
- current portlet action responsehandler
- chosen handler to execute, for type and/or instance examinationex
- exception thrown on handler execution, if any (only included as additional context information for the case where a handler threw an exception; request execution may have failed even when this argument isnull
)- 抛出:
Exception
- in case of errors
preHandleRender
boolean preHandleRender(RenderRequest request, RenderResponse response, Object handler) throws Exception
Intercept the execution of a handler in the render phase.Called after a HandlerMapping determines an appropriate handler object to handle a
RenderRequest
, but before said HandlerAdapter actually invokes the handler.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can decide to abort the execution chain, typically throwing an exception or writing a custom response.- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance evaluation- 返回:
true
if the execution chain should proceed with the next interceptor or the handler itself. Else,DispatcherPortlet
assumes that this interceptor has already dealt with the response itself- 抛出:
Exception
- in case of errors
postHandleRender
void postHandleRender(RenderRequest request, RenderResponse response, Object handler, ModelAndView modelAndView) throws Exception
Intercept the execution of a handler in the render phase.Called after a
HandlerAdapter
actually invoked the handler, but before theDispatcherPortlet
renders the view. Can thus expose additional model objects to the view via the givenModelAndView
.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can post-process an execution, getting applied in inverse order of the execution chain.- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance examinationmodelAndView
- theModelAndView
that the handler returned (can also benull
)- 抛出:
Exception
- in case of errors
afterRenderCompletion
void afterRenderCompletion(RenderRequest request, RenderResponse response, Object handler, Exception ex) throws Exception
Callback after completion of request processing, that is, after rendering the view. Will be called on any outcome of handler execution, thus allowing for proper resource cleanup.Note: Will only be called if this interceptor's
preHandleRender(javax.portlet.RenderRequest, javax.portlet.RenderResponse, Object)
method has successfully completed and returnedtrue
!- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance examinationex
- exception thrown on handler execution, if any- 抛出:
Exception
- in case of errors
preHandleResource
boolean preHandleResource(ResourceRequest request, ResourceResponse response, Object handler) throws Exception
Intercept the execution of a handler in the render phase.Called after a HandlerMapping determines an appropriate handler object to handle a
RenderRequest
, but before said HandlerAdapter actually invokes the handler.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can decide to abort the execution chain, typically throwing an exception or writing a custom response.- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance evaluation- 返回:
true
if the execution chain should proceed with the next interceptor or the handler itself. Else,DispatcherPortlet
assumes that this interceptor has already dealt with the response itself- 抛出:
Exception
- in case of errors
postHandleResource
void postHandleResource(ResourceRequest request, ResourceResponse response, Object handler, ModelAndView modelAndView) throws Exception
Intercept the execution of a handler in the render phase.Called after a
HandlerAdapter
actually invoked the handler, but before theDispatcherPortlet
renders the view. Can thus expose additional model objects to the view via the givenModelAndView
.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can post-process an execution, getting applied in inverse order of the execution chain.- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance examinationmodelAndView
- theModelAndView
that the handler returned (can also benull
)- 抛出:
Exception
- in case of errors
afterResourceCompletion
void afterResourceCompletion(ResourceRequest request, ResourceResponse response, Object handler, Exception ex) throws Exception
Callback after completion of request processing, that is, after rendering the view. Will be called on any outcome of handler execution, thus allowing for proper resource cleanup.Note: Will only be called if this interceptor's
preHandleRender(javax.portlet.RenderRequest, javax.portlet.RenderResponse, Object)
method has successfully completed and returnedtrue
!- 参数:
request
- current portlet render requestresponse
- current portlet render responsehandler
- chosen handler to execute, for type and/or instance examinationex
- exception thrown on handler execution, if any- 抛出:
Exception
- in case of errors
preHandleEvent
boolean preHandleEvent(EventRequest request, EventResponse response, Object handler) throws Exception
Intercept the execution of a handler in the action phase.Called after a HandlerMapping determines an appropriate handler object to handle an
ActionRequest
, but before said HandlerAdapter actually invokes the handler.DispatcherPortlet
processes a handler in an execution chain, consisting of any number of interceptors, with the handler itself at the end. With this method, each interceptor can decide to abort the execution chain, typically throwing an exception or writing a custom response.- 参数:
request
- current portlet action requestresponse
- current portlet action responsehandler
- chosen handler to execute, for type and/or instance evaluation- 返回:
true
if the execution chain should proceed with the next interceptor or the handler itself. Else,DispatcherPortlet
assumes that this interceptor has already dealt with the response itself- 抛出:
Exception
- in case of errors
afterEventCompletion
void afterEventCompletion(EventRequest request, EventResponse response, Object handler, Exception ex) throws Exception
Callback after completion of request processing in the action phase, that is, after rendering the view. Will be called on any outcome of handler execution, thus allowing for proper resource cleanup.Note: Will only be called if this interceptor's
preHandleAction(javax.portlet.ActionRequest, javax.portlet.ActionResponse, Object)
method has successfully completed and returnedtrue
!- 参数:
request
- current portlet action requestresponse
- current portlet action responsehandler
- chosen handler to execute, for type and/or instance examinationex
- exception thrown on handler execution, if any (only included as additional context information for the case where a handler threw an exception; request execution may have failed even when this argument isnull
)- 抛出:
Exception
- in case of errors