Package org.axonframework.commandhandling.callbacks

Class FutureCallback<C,R>

java.lang.Object

java.util.concurrent.CompletableFuture<CommandResultMessage<? extends R>>

org.axonframework.commandhandling.callbacks.FutureCallback<C,R>

Type Parameters:

C - The type of payload of the dispatched command

R - the type of result of the command handling

All Implemented Interfaces:

CompletionStage<CommandResultMessage<? extends R>>, Future<CommandResultMessage<? extends R>>, CommandCallback<C,R>

public class FutureCallback<C,R>
extends CompletableFuture<CommandResultMessage<? extends R>>
implements CommandCallback<C,R>

Command Handler Callback that allows the dispatching thread to wait for the result of the callback, using the Future mechanism. This callback allows the caller to synchronize calls when an asynchronous command bus is being used.

Since:

0.6

Author:

Allard Buijze

Nested Class Summary

Nested classes/interfaces inherited from class java.util.concurrent.CompletableFuture

CompletableFuture.AsynchronousCompletionTask

Nested classes/interfaces inherited from interface java.util.concurrent.Future

Future.State

Constructor Summary

Constructors

Constructor	Description
FutureCallback()

Method Summary

Modifier and Type	Method	Description
boolean	awaitCompletion(long timeout, TimeUnit unit)	Wait for completion of the command, or for the timeout to expire.
CommandResultMessage<? extends R>	getResult()	Waits if necessary for the command handling to complete, and then returns its result.
CommandResultMessage<? extends R>	getResult(long timeout, TimeUnit unit)	Waits if necessary for at most the given time for the command handling to complete, and then retrieves its result, if available.
void	onResult(CommandMessage<? extends C> commandMessage, CommandResultMessage<? extends R> commandResultMessage)	Invoked when command handling execution is completed.

Methods inherited from class java.util.concurrent.CompletableFuture

acceptEither, acceptEitherAsync, acceptEitherAsync, allOf, anyOf, applyToEither, applyToEitherAsync, applyToEitherAsync, cancel, complete, completeAsync, completeAsync, completedFuture, completedStage, completeExceptionally, completeOnTimeout, copy, defaultExecutor, delayedExecutor, delayedExecutor, exceptionally, exceptionallyAsync, exceptionallyAsync, exceptionallyCompose, exceptionallyComposeAsync, exceptionallyComposeAsync, exceptionNow, failedFuture, failedStage, get, get, getNow, getNumberOfDependents, handle, handleAsync, handleAsync, isCancelled, isCompletedExceptionally, isDone, join, minimalCompletionStage, newIncompleteFuture, obtrudeException, obtrudeValue, orTimeout, resultNow, runAfterBoth, runAfterBothAsync, runAfterBothAsync, runAfterEither, runAfterEitherAsync, runAfterEitherAsync, runAsync, runAsync, state, supplyAsync, supplyAsync, thenAccept, thenAcceptAsync, thenAcceptAsync, thenAcceptBoth, thenAcceptBothAsync, thenAcceptBothAsync, thenApply, thenApplyAsync, thenApplyAsync, thenCombine, thenCombineAsync, thenCombineAsync, thenCompose, thenComposeAsync, thenComposeAsync, thenRun, thenRunAsync, thenRunAsync, toCompletableFuture, toString, whenComplete, whenCompleteAsync, whenCompleteAsync

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.commandhandling.CommandCallback

wrap

Constructor Details

FutureCallback

public FutureCallback()

Method Details

onResult

public void onResult(@Nonnull
 CommandMessage<? extends C> commandMessage,
 @Nonnull
 CommandResultMessage<? extends R> commandResultMessage)

Description copied from interface: CommandCallback

Invoked when command handling execution is completed.

Specified by:

onResult in interface CommandCallback<C,R>

Parameters:

commandMessage - the CommandMessage that was dispatched

commandResultMessage - the CommandResultMessage of the command handling execution

getResult

public CommandResultMessage<? extends R> getResult()

Waits if necessary for the command handling to complete, and then returns its result.

Unlike CompletableFuture.get(long, java.util.concurrent.TimeUnit), this method will throw the original exception. Only checked exceptions are wrapped in a CommandExecutionException.

If the thread is interrupted while waiting, the interrupt flag is set back on the thread, and null is returned. To distinguish between an interrupt and a null result, use the CompletableFuture.isDone() method.

Returns:

the result of the command handler execution.

See Also:

• CompletableFuture.get()

getResult

public CommandResultMessage<? extends R> getResult(long timeout,
 TimeUnit unit)

Waits if necessary for at most the given time for the command handling to complete, and then retrieves its result, if available.

Unlike CompletableFuture.get(long, java.util.concurrent.TimeUnit), this method will report the original exception from within a CommandResultMessage, rather than throwing an ExecutionException.

If the timeout expired or the thread is interrupted before completion, the returned CommandResultMessage will contain an InterruptedException or TimeoutException. In case of an interrupt, the interrupt flag will have been set back on the thread.

Parameters:

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

the result of the command handler execution.

awaitCompletion

public boolean awaitCompletion(long timeout,
 TimeUnit unit)

Wait for completion of the command, or for the timeout to expire.

Parameters:

timeout - The amount of time to wait for command processing to complete

unit - The unit in which the timeout is expressed

Returns:

true if command processing completed before the timeout expired, otherwise false.