Spring Web 6.1.4 · org.springframework.web.context.request.async.DeferredResult

DeferredResult provides an alternative to using a Callable for asynchronous request processing. While a Callable is executed concurrently on behalf of the application, with a DeferredResult the application can produce the result from a thread of its choice.

Subclasses can extend this class to easily associate additional data or behavior with the DeferredResult. For example, one might want to associate the user used to create the DeferredResult by extending the class and adding an additional property for the user. In this way, the user could easily be accessed later without the need to use a data structure to do the mapping.

An example of associating additional behavior to this class might be realized by extending the class to implement an additional interface. For example, one might want to implement Comparable so that when the DeferredResult is added to a PriorityQueue it is handled in the correct order.

Nested and Inner Type Summary

Modifier and Type	Class and Description
public static interface	DeferredResult.DeferredResultHandler Handles a DeferredResult value when set.

Field Summary

Modifier and Type	Field and Description
private Runnable	completionCallback
private Consumer<Throwable>	errorCallback
private volatile boolean	expired
private static final Log	logger
private volatile Object	result
private static final Object	RESULT_NONE
private DeferredResult.DeferredResultHandler	resultHandler
private Runnable	timeoutCallback
private final Supplier<?>	timeoutResult
private final Long	timeoutValue

Constructor Summary

Access	Constructor and Description
public	DeferredResult() Create a DeferredResult.
public	DeferredResult(Long timeout value in milliseconds timeoutValue) Create a DeferredResult with a custom timeout value.
public	DeferredResult(Long timeout value in milliseconds (ignored if `null`) timeoutValue, Object the result to use timeoutResult) Create a DeferredResult with a timeout value and a default result to use in case of timeout.
public	DeferredResult(Long timeout value in milliseconds (ignored if `null`) timeoutValue, Supplier<?> the result supplier to use timeoutResult) Variant of `DeferredResult(Long, Object)` that accepts a dynamic fallback value based on a `Supplier`.

Method Summary

Modifier and Type	Method and Description
pack-priv final DeferredResultProcessingInterceptor	getInterceptor()
public Object	getResult() Return the result, or `null` if the result wasn't set.
pack-priv final Long	getTimeoutValue() Return the configured timeout value in milliseconds.
public boolean	hasResult() Return `true` if the DeferredResult has been set.
public final boolean	isSetOrExpired() Return `true` if this DeferredResult is no longer usable either because it was previously set or because the underlying request expired.
public void	onCompletion(Runnable callback) Register code to invoke when the async request completes.
public void	onError(Consumer<Throwable> callback) Register code to invoke when an error occurred during the async request.
public void	onTimeout(Runnable callback) Register code to invoke when the async request times out.
public boolean	Returns: `true` if the result was set to the error value and passed on for handling; `false` if the result was already set or the async request expired setErrorResult(Object the error result value result) Set an error value for the `DeferredResult` and handle it.
public boolean	Returns: `true` if the result was set and passed on for handling; `false` if the result was already set or the async request expired setResult(T the value to set result) Set the value for the DeferredResult and handle it.
public final void	setResultHandler(DeferredResult.DeferredResultHandler the handler resultHandler) Provide a handler to use to handle the result value.
private boolean	setResultInternal(Object result)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

completionCallback	back to summary
private Runnable completionCallback Annotations @Nullable

errorCallback	back to summary
private Consumer<Throwable> errorCallback Annotations @Nullable

expired	back to summary
private volatile boolean expired

logger	back to summary
private static final Log logger

result	back to summary
private volatile Object result Annotations @Nullable

RESULT_NONE	back to summary
private static final Object RESULT_NONE

resultHandler	back to summary
private DeferredResult.DeferredResultHandler resultHandler Annotations @Nullable

timeoutCallback	back to summary
private Runnable timeoutCallback Annotations @Nullable

timeoutResult	back to summary
private final Supplier<?> timeoutResult

timeoutValue	back to summary
private final Long timeoutValue Annotations @Nullable

Constructor Detail

DeferredResult	back to summary
public DeferredResult() Create a DeferredResult.

DeferredResult	back to summary
public DeferredResult(Long timeoutValue) Create a DeferredResult with a custom timeout value. By default not set in which case the default configured in the MVC Java Config or the MVC namespace is used, or if that's not set, then the timeout depends on the default of the underlying server. Parameters timeoutValue:Long timeout value in milliseconds

DeferredResult

back to summary

public DeferredResult(Long timeoutValue)

Create a DeferredResult with a custom timeout value.

By default not set in which case the default configured in the MVC Java Config or the MVC namespace is used, or if that's not set, then the timeout depends on the default of the underlying server.

Parameters

timeoutValue:Long: timeout value in milliseconds

DeferredResult back to summary

DeferredResult	back to summary
public DeferredResult(Long timeoutValue, Object timeoutResult) Create a DeferredResult with a timeout value and a default result to use in case of timeout. Parameters timeoutValue:Long timeout value in milliseconds (ignored if `null`) timeoutResult:Object the result to use

public DeferredResult(Long timeoutValue, Object timeoutResult)

Create a DeferredResult with a timeout value and a default result to use in case of timeout.

Parameters

timeoutValue:Long: timeout value in milliseconds (ignored if null)
timeoutResult:Object: the result to use

DeferredResult back to summary

DeferredResult	back to summary
public DeferredResult(Long timeoutValue, Supplier<?> timeoutResult) Variant of `DeferredResult(Long, Object)` that accepts a dynamic fallback value based on a `Supplier`. Parameters timeoutValue:Long timeout value in milliseconds (ignored if `null`) timeoutResult:Supplier<?> the result supplier to use Since 5.1.1

public DeferredResult(Long timeoutValue, Supplier<?> timeoutResult)

Variant of DeferredResult(Long, Object) that accepts a dynamic fallback value based on a Supplier.

Parameters

timeoutValue:Long: timeout value in milliseconds (ignored if null)
timeoutResult:Supplier<?>: the result supplier to use

Since

5.1.1

Method Detail

getInterceptor	back to summary
pack-priv final DeferredResultProcessingInterceptor getInterceptor()

getResult back to summary

getResult	back to summary
public Object getResult() Return the result, or `null` if the result wasn't set. Since the result can also be `null`, it is recommended to use `hasResult()` first to check if there is a result prior to calling this method. Annotations @Nullable Since 4.0

public Object getResult()

Return the result, or null if the result wasn't set. Since the result can also be null, it is recommended to use hasResult() first to check if there is a result prior to calling this method.

Annotations

@Nullable

Since

4.0

getTimeoutValue	back to summary
pack-priv final Long getTimeoutValue() Return the configured timeout value in milliseconds. Annotations @Nullable

getTimeoutValue

back to summary

pack-priv final Long getTimeoutValue()

Return the configured timeout value in milliseconds.

Annotations

@Nullable

hasResult back to summary

hasResult	back to summary
public boolean hasResult() Return `true` if the DeferredResult has been set. Since 4.0

public boolean hasResult()

Return true if the DeferredResult has been set.

Since: 4.0

isSetOrExpired back to summary

isSetOrExpired	back to summary
public final boolean isSetOrExpired() Return `true` if this DeferredResult is no longer usable either because it was previously set or because the underlying request expired. The result may have been set with a call to `setResult(Object)`, or `setErrorResult(Object)`, or as a result of a timeout, if a timeout result was provided to the constructor. The request may also expire due to a timeout or network error.

public final boolean isSetOrExpired()

Return true if this DeferredResult is no longer usable either because it was previously set or because the underlying request expired.

The result may have been set with a call to setResult(Object), or setErrorResult(Object), or as a result of a timeout, if a timeout result was provided to the constructor. The request may also expire due to a timeout or network error.

onCompletion back to summary

onCompletion	back to summary
public void onCompletion(Runnable callback) Register code to invoke when the async request completes. This method is called from a container thread when an async request completed for any reason including timeout and network error. This is useful for detecting that a `DeferredResult` instance is no longer usable.

public void onCompletion(Runnable callback)

This method is called from a container thread when an async request completed for any reason including timeout and network error. This is useful for detecting that a DeferredResult instance is no longer usable.

onError back to summary

onError	back to summary
public void onError(Consumer<Throwable> callback) Register code to invoke when an error occurred during the async request. This method is called from a container thread when an error occurs while processing an async request before the `DeferredResult` has been populated. It may invoke `setResult` or `setErrorResult` to resume processing. Since 5.0

public void onError(Consumer<Throwable> callback)

This method is called from a container thread when an error occurs while processing an async request before the DeferredResult has been populated. It may invoke setResult or setErrorResult to resume processing.

Since: 5.0

onTimeout back to summary

onTimeout	back to summary
public void onTimeout(Runnable callback) Register code to invoke when the async request times out. This method is called from a container thread when an async request times out before the `DeferredResult` has been populated. It may invoke `setResult` or `setErrorResult` to resume processing.

public void onTimeout(Runnable callback)

This method is called from a container thread when an async request times out before the DeferredResult has been populated. It may invoke setResult or setErrorResult to resume processing.

setErrorResult back to summary

setErrorResult	back to summary
public boolean setErrorResult(Object result) Set an error value for the `DeferredResult` and handle it. The value may be an `Exception` or `Throwable` in which case it will be processed as if a handler raised the exception. Parameters result:Object the error result value Returns:boolean `true` if the result was set to the error value and passed on for handling; `false` if the result was already set or the async request expired See Also `isSetOrExpired()`

public boolean setErrorResult(Object result)

Set an error value for the DeferredResult and handle it. The value may be an Exception or Throwable in which case it will be processed as if a handler raised the exception.

Parameters

result:Object: the error result value

Returns:boolean

true if the result was set to the error value and passed on for handling; false if the result was already set or the async request expired

See Also

isSetOrExpired()

setResult back to summary

setResult	back to summary
public boolean setResult(T result) Set the value for the DeferredResult and handle it. Parameters result:T the value to set Returns:boolean `true` if the result was set and passed on for handling; `false` if the result was already set or the async request expired See Also `isSetOrExpired()`

public boolean setResult(T result)

Set the value for the DeferredResult and handle it.

Parameters

result:T: the value to set

Returns:boolean

true if the result was set and passed on for handling; false if the result was already set or the async request expired

See Also

isSetOrExpired()

setResultHandler back to summary

setResultHandler	back to summary
public final void setResultHandler(DeferredResult.DeferredResultHandler resultHandler) Provide a handler to use to handle the result value. Parameters resultHandler:DeferredResult.DeferredResultHandler the handler See Also `DeferredResultProcessingInterceptor`

public final void setResultHandler(DeferredResult.DeferredResultHandler resultHandler)

Provide a handler to use to handle the result value.

Parameters

resultHandler:DeferredResult.DeferredResultHandler: the handler

See Also

DeferredResultProcessingInterceptor

setResultInternal	back to summary
private boolean setResultInternal(Object result)

public Class DeferredResult<T>

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public Interface DeferredResult.DeferredResultHandler

Method Summary

Method Detail