Class OncePerRequestFilter
- All Implemented Interfaces:
Filter
,Aware
,BeanNameAware
,DisposableBean
,InitializingBean
,EnvironmentAware
,EnvironmentCapable
,ServletContextAware
- Direct Known Subclasses:
AbstractRequestLoggingFilter
,CharacterEncodingFilter
,CorsFilter
,FormContentFilter
,ForwardedHeaderFilter
,HiddenHttpMethodFilter
,MultipartFilter
,OpenEntityManagerInViewFilter
,OpenSessionInViewFilter
,RelativeRedirectFilter
,RequestContextFilter
,ServerHttpObservationFilter
,ShallowEtagHeaderFilter
,UrlHandlerFilter
doFilterInternal(jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse, jakarta.servlet.FilterChain)
method with HttpServletRequest and HttpServletResponse arguments.
A filter may be invoked as part of a
REQUEST
or
ASYNC
dispatches that occur in
separate threads. A filter can be configured in web.xml
whether it
should be involved in async dispatches. However, in some cases servlet
containers assume different default configuration. Therefore, subclasses can
override the method shouldNotFilterAsyncDispatch()
to declare
statically if they should indeed be invoked, once, during both types
of dispatches in order to provide thread initialization, logging, security,
and so on. This mechanism complements and does not replace the need to
configure a filter in web.xml
with dispatcher types.
Subclasses may use isAsyncDispatch(HttpServletRequest)
to
determine when a filter is invoked as part of an async dispatch, and use
isAsyncStarted(HttpServletRequest)
to determine when the request
has been placed in async mode and therefore the current dispatch won't be
the last one for the given request.
Yet another dispatch type that also occurs in its own thread is
ERROR
. Subclasses can override
shouldNotFilterErrorDispatch()
if they wish to declare statically
if they should be invoked once during error dispatches.
The getAlreadyFilteredAttributeName()
method determines how to
identify that a request is already filtered. The default implementation is
based on the configured name of the concrete filter instance.
- Since:
- 06.12.2003
- Author:
- Juergen Hoeller, Rossen Stoyanchev, Sam Brannen
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final String
Suffix that gets appended to the filter name for the "already filtered" request attribute.Fields inherited from class org.springframework.web.filter.GenericFilterBean
logger
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionfinal void
doFilter
(ServletRequest request, ServletResponse response, FilterChain filterChain) ThisdoFilter
implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there.protected abstract void
doFilterInternal
(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) Same contract as fordoFilter
, but guaranteed to be just invoked once per request within a single request thread.protected void
doFilterNestedErrorDispatch
(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) Typically an ERROR dispatch happens after the REQUEST dispatch completes, and the filter chain starts anew.protected String
Return the name of the request attribute that identifies that a request is already filtered.protected boolean
isAsyncDispatch
(HttpServletRequest request) The dispatcher typejakarta.servlet.DispatcherType.ASYNC
means a filter can be invoked in more than one thread over the course of a single request.protected boolean
isAsyncStarted
(HttpServletRequest request) Whether request processing is in asynchronous mode meaning that the response will not be committed after the current thread is exited.protected boolean
shouldNotFilter
(HttpServletRequest request) Can be overridden in subclasses for custom filtering control, returningtrue
to avoid filtering of the given request.protected boolean
The dispatcher typejakarta.servlet.DispatcherType.ASYNC
means a filter can be invoked in more than one thread over the course of a single request.protected boolean
Whether to filter error dispatches such as when the servlet container processes and error mapped inweb.xml
.Methods inherited from class org.springframework.web.filter.GenericFilterBean
addRequiredProperty, afterPropertiesSet, createEnvironment, destroy, getEnvironment, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, initFilterBean, setBeanName, setEnvironment, setServletContext
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Field Details
-
ALREADY_FILTERED_SUFFIX
Suffix that gets appended to the filter name for the "already filtered" request attribute.
-
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Constructor Details
-
OncePerRequestFilter
public OncePerRequestFilter()
-
-
Method Details
-
doFilter
public final void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws ServletException, IOException ThisdoFilter
implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there. -
isAsyncDispatch
The dispatcher typejakarta.servlet.DispatcherType.ASYNC
means a filter can be invoked in more than one thread over the course of a single request. This method returnstrue
if the filter is currently executing within an asynchronous dispatch.- Parameters:
request
- the current request- Since:
- 3.2
- See Also:
-
isAsyncStarted
Whether request processing is in asynchronous mode meaning that the response will not be committed after the current thread is exited.- Parameters:
request
- the current request- Since:
- 3.2
- See Also:
-
getAlreadyFilteredAttributeName
Return the name of the request attribute that identifies that a request is already filtered.The default implementation takes the configured name of the concrete filter instance and appends ".FILTERED". If the filter is not fully initialized, it falls back to its class name.
-
shouldNotFilter
Can be overridden in subclasses for custom filtering control, returningtrue
to avoid filtering of the given request.The default implementation always returns
false
.- Parameters:
request
- current HTTP request- Returns:
- whether the given request should not be filtered
- Throws:
ServletException
- in case of errors
-
shouldNotFilterAsyncDispatch
protected boolean shouldNotFilterAsyncDispatch()The dispatcher typejakarta.servlet.DispatcherType.ASYNC
means a filter can be invoked in more than one thread over the course of a single request. Some filters only need to filter the initial thread (e.g. request wrapping) while others may need to be invoked at least once in each additional thread for example for setting up thread locals or to perform final processing at the very end.Note that although a filter can be mapped to handle specific dispatcher types via
web.xml
or in Java through theServletContext
, servlet containers may enforce different defaults with respect to dispatcher types. This flag enforces the design intent of the filter.The default return value is "true", which means the filter will not be invoked during subsequent async dispatches. If "false", the filter will be invoked during async dispatches with the same guarantees of being invoked only once during a request within a single thread.
- Since:
- 3.2
-
shouldNotFilterErrorDispatch
protected boolean shouldNotFilterErrorDispatch()Whether to filter error dispatches such as when the servlet container processes and error mapped inweb.xml
. The default return value is "true", which means the filter will not be invoked in case of an error dispatch.- Since:
- 3.2
-
doFilterInternal
protected abstract void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException Same contract as fordoFilter
, but guaranteed to be just invoked once per request within a single request thread. SeeshouldNotFilterAsyncDispatch()
for details.Provides HttpServletRequest and HttpServletResponse arguments instead of the default ServletRequest and ServletResponse ones.
- Throws:
ServletException
IOException
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doFilterNestedErrorDispatch
protected void doFilterNestedErrorDispatch(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException Typically an ERROR dispatch happens after the REQUEST dispatch completes, and the filter chain starts anew. On some servers however the ERROR dispatch may be nested within the REQUEST dispatch, e.g. as a result of callingsendError
on the response. In that case we are still in the filter chain, on the same thread, but the request and response have been switched to the original, unwrapped ones.Sub-classes may use this method to filter such nested ERROR dispatches and re-apply wrapping on the request or response.
ThreadLocal
context, if any, should still be active as we are still nested within the filter chain.- Throws:
ServletException
IOException
- Since:
- 5.1.9
-