Class WebAsyncManager
- java.lang.Object
- org.springframework.web.context.request.async.WebAsyncManager
public final class WebAsyncManager extends Object
The central class for managing asynchronous request processing, mainly intended as an SPI and not typically used directly by application classes.An async scenario starts with request processing as usual in a thread (T1). Concurrent request handling can be initiated by calling
startCallableProcessing
orstartDeferredResultProcessing
, both of which produce a result in a separate thread (T2). The result is saved and the request dispatched to the container, to resume processing with the saved result in a third thread (T3). Within the dispatched thread (T3), the saved result can be accessed viagetConcurrentResult()
or its presence detected viahasConcurrentResult()
.- Since:
- 3.2
- Author:
- Rossen Stoyanchev, Juergen Hoeller
- See Also:
AsyncWebRequestInterceptor
,AsyncHandlerInterceptor
,OncePerRequestFilter.shouldNotFilterAsyncDispatch()
,OncePerRequestFilter.isAsyncDispatch(javax.servlet.http.HttpServletRequest)
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clearConcurrentResult()
Clear concurrentResult and concurrentResultContext.CallableProcessingInterceptor
getCallableInterceptor(Object key)
Get theCallableProcessingInterceptor
registered under the given key.Object
getConcurrentResult()
Provides access to the result from concurrent handling.Object[]
getConcurrentResultContext()
Provides access to additional processing context saved at the start of concurrent handling.DeferredResultProcessingInterceptor
getDeferredResultInterceptor(Object key)
Get theDeferredResultProcessingInterceptor
registered under the given key.boolean
hasConcurrentResult()
Whether a result value exists as a result of concurrent handling.boolean
isConcurrentHandlingStarted()
Whether the selected handler for the current request chose to handle the request asynchronously.void
registerCallableInterceptor(Object key, CallableProcessingInterceptor interceptor)
Register aCallableProcessingInterceptor
under the given key.void
registerCallableInterceptors(CallableProcessingInterceptor... interceptors)
Register aCallableProcessingInterceptor
without a key.void
registerDeferredResultInterceptor(Object key, DeferredResultProcessingInterceptor interceptor)
Register aDeferredResultProcessingInterceptor
under the given key.void
registerDeferredResultInterceptors(DeferredResultProcessingInterceptor... interceptors)
Register one or moreDeferredResultProcessingInterceptor
s without a specified key.void
setAsyncWebRequest(AsyncWebRequest asyncWebRequest)
Configure theAsyncWebRequest
to use.void
setTaskExecutor(AsyncTaskExecutor taskExecutor)
Configure an AsyncTaskExecutor for use with concurrent processing viastartCallableProcessing(Callable, Object...)
.void
startCallableProcessing(Callable<?> callable, Object... processingContext)
Start concurrent request processing and execute the given task with anAsyncTaskExecutor
.void
startCallableProcessing(WebAsyncTask<?> webAsyncTask, Object... processingContext)
Use the givenWebAsyncTask
to configure the task executor as well as the timeout value of theAsyncWebRequest
before delegating tostartCallableProcessing(Callable, Object...)
.void
startDeferredResultProcessing(DeferredResult<?> deferredResult, Object... processingContext)
Start concurrent request processing and initialize the givenDeferredResult
with aDeferredResult.DeferredResultHandler
that saves the result and dispatches the request to resume processing of that result.
Method Detail
setAsyncWebRequest
public void setAsyncWebRequest(AsyncWebRequest asyncWebRequest)
Configure theAsyncWebRequest
to use. This property may be set more than once during a single request to accurately reflect the current state of the request (e.g. following a forward, request/response wrapping, etc). However, it should not be set while concurrent handling is in progress, i.e. whileisConcurrentHandlingStarted()
istrue
.- Parameters:
asyncWebRequest
- the web request to use
setTaskExecutor
public void setTaskExecutor(AsyncTaskExecutor taskExecutor)
Configure an AsyncTaskExecutor for use with concurrent processing viastartCallableProcessing(Callable, Object...)
.By default a
SimpleAsyncTaskExecutor
instance is used.
isConcurrentHandlingStarted
public boolean isConcurrentHandlingStarted()
Whether the selected handler for the current request chose to handle the request asynchronously. A return value of "true" indicates concurrent handling is under way and the response will remain open. A return value of "false" means concurrent handling was either not started or possibly that it has completed and the request was dispatched for further processing of the concurrent result.
hasConcurrentResult
public boolean hasConcurrentResult()
Whether a result value exists as a result of concurrent handling.
getConcurrentResult
public Object getConcurrentResult()
Provides access to the result from concurrent handling.- Returns:
- an Object, possibly an
Exception
orThrowable
if concurrent handling raised one. - See Also:
clearConcurrentResult()
getConcurrentResultContext
public Object[] getConcurrentResultContext()
Provides access to additional processing context saved at the start of concurrent handling.- See Also:
clearConcurrentResult()
getCallableInterceptor
public CallableProcessingInterceptor getCallableInterceptor(Object key)
Get theCallableProcessingInterceptor
registered under the given key.- Parameters:
key
- the key- Returns:
- the interceptor registered under that key, or
null
if none
getDeferredResultInterceptor
public DeferredResultProcessingInterceptor getDeferredResultInterceptor(Object key)
Get theDeferredResultProcessingInterceptor
registered under the given key.- Parameters:
key
- the key- Returns:
- the interceptor registered under that key, or
null
if none
registerCallableInterceptor
public void registerCallableInterceptor(Object key, CallableProcessingInterceptor interceptor)
Register aCallableProcessingInterceptor
under the given key.- Parameters:
key
- the keyinterceptor
- the interceptor to register
registerCallableInterceptors
public void registerCallableInterceptors(CallableProcessingInterceptor... interceptors)
Register aCallableProcessingInterceptor
without a key. The key is derived from the class name and hashcode.- Parameters:
interceptors
- one or more interceptors to register
registerDeferredResultInterceptor
public void registerDeferredResultInterceptor(Object key, DeferredResultProcessingInterceptor interceptor)
Register aDeferredResultProcessingInterceptor
under the given key.- Parameters:
key
- the keyinterceptor
- the interceptor to register
registerDeferredResultInterceptors
public void registerDeferredResultInterceptors(DeferredResultProcessingInterceptor... interceptors)
Register one or moreDeferredResultProcessingInterceptor
s without a specified key. The default key is derived from the interceptor class name and hash code.- Parameters:
interceptors
- one or more interceptors to register
clearConcurrentResult
public void clearConcurrentResult()
Clear concurrentResult and concurrentResultContext.
startCallableProcessing
public void startCallableProcessing(Callable<?> callable, Object... processingContext) throws Exception
Start concurrent request processing and execute the given task with anAsyncTaskExecutor
. The result from the task execution is saved and the request dispatched in order to resume processing of that result. If the task raises an Exception then the saved result will be the raised Exception.- Parameters:
callable
- a unit of work to be executed asynchronouslyprocessingContext
- additional context to save that can be accessed viagetConcurrentResultContext()
- Throws:
Exception
- if concurrent processing failed to start- See Also:
getConcurrentResult()
,getConcurrentResultContext()
startCallableProcessing
public void startCallableProcessing(WebAsyncTask<?> webAsyncTask, Object... processingContext) throws Exception
Use the givenWebAsyncTask
to configure the task executor as well as the timeout value of theAsyncWebRequest
before delegating tostartCallableProcessing(Callable, Object...)
.- Parameters:
webAsyncTask
- a WebAsyncTask containing the targetCallable
processingContext
- additional context to save that can be accessed viagetConcurrentResultContext()
- Throws:
Exception
- if concurrent processing failed to start
startDeferredResultProcessing
public void startDeferredResultProcessing(DeferredResult<?> deferredResult, Object... processingContext) throws Exception
Start concurrent request processing and initialize the givenDeferredResult
with aDeferredResult.DeferredResultHandler
that saves the result and dispatches the request to resume processing of that result. TheAsyncWebRequest
is also updated with a completion handler that expires theDeferredResult
and a timeout handler assuming theDeferredResult
has a default timeout result.- Parameters:
deferredResult
- the DeferredResult instance to initializeprocessingContext
- additional context to save that can be accessed viagetConcurrentResultContext()
- Throws:
Exception
- if concurrent processing failed to start- See Also:
getConcurrentResult()
,getConcurrentResultContext()