org.springframework.web.context.request.async

Class DeferredResult<T>

java.lang.Object

org.springframework.web.context.request.async.DeferredResult<T>

public final class DeferredResult<T>
extends java.lang.Object

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.

Since:

3.2

Author:

Rossen Stoyanchev

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

Constructor and Description
DeferredResult() Create a DeferredResult.
DeferredResult(long timeout) Create a DeferredResult with a timeout.
DeferredResult(java.lang.Long timeout, java.lang.Object timeoutResult) Create a DeferredResult with a timeout and a default result to use on timeout.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Long	getTimeoutMilliseconds() Return the configured timeout value in milliseconds.
boolean	isSetOrExpired() Whether the DeferredResult can no longer be set either because the async request expired or because it was already set.
boolean	setErrorResult(java.lang.Object result) Set an error result value and pass it on for handling.
boolean	setResult(T result) Set the result value and pass it on for handling.
void	setResultHandler(DeferredResult.DeferredResultHandler resultHandler) Set a handler to handle the result when set.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DeferredResult

public DeferredResult()

Create a DeferredResult.

DeferredResult

public DeferredResult(long timeout)

Create a DeferredResult with a timeout.

Parameters:

timeout - timeout value in milliseconds

DeferredResult

public DeferredResult(java.lang.Long timeout,
              java.lang.Object timeoutResult)

Create a DeferredResult with a timeout and a default result to use on timeout.

Parameters:

timeout - timeout value in milliseconds; ignored if null

timeoutResult - the result to use, possibly null

Method Detail

getTimeoutMilliseconds

public java.lang.Long getTimeoutMilliseconds()

Return the configured timeout value in milliseconds.

setResultHandler

public void setResultHandler(DeferredResult.DeferredResultHandler resultHandler)

Set a handler to handle the result when set. Normally applications do not use this method at runtime but may do so during testing.

setResult

public boolean setResult(T result)

Set the result value and pass it on for handling.

Parameters:

result - the result value

Returns:

"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()

setErrorResult

public boolean setErrorResult(java.lang.Object result)

Set an error result value and pass it on for handling. If the result is an Exception or Throwable, it will be processed as though the controller raised the exception. Otherwise it will be processed as if the controller returned the given result.

Parameters:

result - the error result value

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.

See Also:

isSetOrExpired()

isSetOrExpired

public boolean isSetOrExpired()

Whether the DeferredResult can no longer be set either because the async request expired or because it was already set.