org.springframework.integration.annotation

Annotation Type Aggregator

@Target(value={METHOD,ANNOTATION_TYPE})
 @Retention(value=RUNTIME)
 @Documented
public @interface Aggregator

Indicates that a method is capable of aggregating messages.

A method annotated with @Aggregator may accept a collection of Messages or Message payloads and should return a single Message or a single Object to be used as a Message payload.

Author:

Marius Bogoevici, Oleg Zhurakousky, Artem Bilan

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	autoStartup The SmartLifecycle autoStartup option.
String	discardChannel
String	inputChannel
String	outputChannel
String	phase Specify a SmartLifecycle phase option.
Poller[]	poller
String	sendPartialResultsOnExpiry Specify whether messages that expired should be aggregated and sent to the outputChannel() or replyChannel from message headers.
String	sendTimeout Specify the maximum amount of time in milliseconds to wait when sending a reply Message to the outputChannel().

Element Detail

inputChannel

public abstract String inputChannel

Returns:

The channel name for receiving messages to be aggregated

Default:

""

outputChannel

public abstract String outputChannel

Returns:

The channel name for sending aggregated result messages

Default:

""

discardChannel

public abstract String discardChannel

Returns:

The channel name for sending discarded messages (due to a timeout)

Default:

""

sendTimeout

public abstract String sendTimeout

Specify the maximum amount of time in milliseconds to wait when sending a reply Message to the outputChannel(). Defaults to -1 - blocking indefinitely. It is applied only if the output channel has some 'sending' limitations, e.g. QueueChannel with a fixed 'capacity' and is currently full. In this case a MessageDeliveryException is thrown. The 'sendTimeout' is ignored in case of AbstractSubscribableChannel implementations. Can be specified as 'property placeholder', e.g. ${spring.integration.sendTimeout}.

Returns:

The timeout for sending results to the reply target (in milliseconds)

Default:

""

sendPartialResultsOnExpiry

public abstract String sendPartialResultsOnExpiry

Specify whether messages that expired should be aggregated and sent to the outputChannel() or replyChannel from message headers. Messages are expired when their containing MessageGroup expires. One of the ways of expiring MessageGroups is by configuring a MessageGroupStoreReaper. However MessageGroups can alternatively be expired by simply calling MessageGroupStore.expireMessageGroup(groupId). That could be accomplished via a ControlBus operation or by simply invoking that method if you have a reference to the MessageGroupStore instance. Defaults to false. * Can be specified as 'property placeholder', e.g. ${spring.integration.sendPartialResultsOnExpiry}.

Returns:

Indicates whether to send an incomplete aggregate on expiry of the message group

Default:

""

autoStartup

public abstract String autoStartup

The SmartLifecycle autoStartup option. Can be specified as 'property placeholder', e.g. ${foo.autoStartup}. Defaults to true.

Returns:

the auto startup boolean flag.

Default:

""

phase

public abstract String phase

Specify a SmartLifecycle phase option. Defaults Integer.MAX_VALUE / 2 for PollingConsumer and Integer.MIN_VALUE for EventDrivenConsumer. Can be specified as 'property placeholder', e.g. ${foo.phase}.

Returns:

the SmartLifecycle phase.

Default:

""

poller

public abstract Poller[] poller

Returns:

the Poller options for a polled endpoint (PollerMetadata). This attribute is an array just to allow an empty default (no poller). Only one Poller element is allowed.

Default:

{}