Package org.axonframework.messaging.core

Class AbstractMessageStream<M extends Message>

java.lang.Object

org.axonframework.messaging.core.AbstractMessageStream<M>

Type Parameters:

M - The type of Message contained in the entries of this stream.

All Implemented Interfaces:

MessageStream<M>

Direct Known Subclasses:

QueueMessageStream

@Internal
public abstract class AbstractMessageStream<M extends Message>
extends Object
implements MessageStream<M>

Abstract implementation of MessageStream that provides basic state management for completion, errors, and callbacks.

Since:

5.1.0

Author:

Jan Galinski

Nested Class Summary

Nested classes/interfaces inherited from interface org.axonframework.messaging.core.MessageStream

MessageStream.Empty<M extends Message>, MessageStream.Entry<M extends Message>, MessageStream.Single<M extends Message>

Constructor Summary

Constructors

Constructor	Description
AbstractMessageStream()

Method Summary

Modifier and Type	Method	Description
protected void	complete()	Completes the stream normally.
protected void	completeExceptionally(Throwable throwable)	Completes the stream with the given throwable.
Optional<Throwable>	error()	Indicates whether any error has been reported in this stream.
protected void	invokeCallbackSafely()	Invokes the registered callback safely, catching any exceptions and completing the stream with that exception.
boolean	isCompleted()	Indicates whether this stream has been completed.
void	setCallback(Runnable callback)	Registers the callback to invoke when entries are available for reading or when the stream completes (either normally or with an error).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.messaging.core.MessageStream

cast, close, concatWith, filter, first, hasNextAvailable, ignoreEntries, map, mapMessage, next, onClose, onComplete, onErrorContinue, onNext, peek, reduce

Constructor Details

AbstractMessageStream

public AbstractMessageStream()

Method Details

setCallback

public void setCallback(Runnable callback)

Description copied from interface: MessageStream

Registers the callback to invoke when entries are available for reading or when the stream completes (either normally or with an error). An invocation of the callback does not in any way guarantee that entries are indeed available, or that the stream has indeed been completed. Implementations may choose to suppress repeated invocations of the callback if no entries have been read in the meantime.

Any previously registered callback is replaced with the given callback.

The callback is called on an arbitrary thread, and it should keep work performed on this thread to a minimum as this may interfere with other callbacks handled by the same thread. Any exception thrown by the callback will result in the stream completing with this exception as the error.

Specified by:

setCallback in interface MessageStream<M extends Message>

Parameters:

callback - The callback to invoke when entries are available for reading, or the stream completes.

invokeCallbackSafely

protected void invokeCallbackSafely()

Invokes the registered callback safely, catching any exceptions and completing the stream with that exception.

complete

protected void complete()

Completes the stream normally.

completeExceptionally

protected void completeExceptionally(Throwable throwable)

Completes the stream with the given throwable.

Parameters:

throwable - The error that caused the stream to complete.

error

public Optional<Throwable> error()

Description copied from interface: MessageStream

Indicates whether any error has been reported in this stream. Implementations may choose to not return any error here until all entries that were available for reading before any error occurred have been consumed.

Specified by:

error in interface MessageStream<M extends Message>

Returns:

An optional containing the possible error this stream completed with.

isCompleted

public boolean isCompleted()

Description copied from interface: MessageStream

Indicates whether this stream has been completed. A completed stream will never return entries from MessageStream.next(), and MessageStream.hasNextAvailable() will always return false. If the stream completed with an error, MessageStream.error() will report so.

Specified by:

isCompleted in interface MessageStream<M extends Message>

Returns:

true if the stream completed, otherwise false.