Package org.springframework.data.mongodb.core.messaging

Class DefaultMessageListenerContainer

java.lang.Object

org.springframework.data.mongodb.core.messaging.DefaultMessageListenerContainer

All Implemented Interfaces:

Lifecycle, Phased, SmartLifecycle, MessageListenerContainer

public class DefaultMessageListenerContainer
extends Object
implements MessageListenerContainer

Simple Executor based MessageListenerContainer implementation for running tasks like listening to MongoDB Change Streams and tailable cursors.
This message container creates long-running tasks that are executed on Executor.

Since:

2.1

Author:

Christoph Strobl, Mark Paluch

Field Summary

Fields inherited from interface org.springframework.context.SmartLifecycle

DEFAULT_PHASE

Constructor Summary

Constructors

Constructor	Description
DefaultMessageListenerContainer(MongoTemplate template)	Create a new DefaultMessageListenerContainer.
DefaultMessageListenerContainer(MongoTemplate template, Executor taskExecutor)	Create a new DefaultMessageListenerContainer running tasks via the given taskExecutor.
DefaultMessageListenerContainer(MongoTemplate template, Executor taskExecutor, ErrorHandler errorHandler)	Create a new DefaultMessageListenerContainer running tasks via the given taskExecutor delegating errors to the given ErrorHandler.

Method Summary

Modifier and Type	Method	Description
int	getPhase()
boolean	isAutoStartup()
boolean	isRunning()
Optional<Subscription>	lookup(SubscriptionRequest<?,?,?> request)	Lookup the given SubscriptionRequest within the container and return the associated Subscription if present.
<S, T> Subscription	register(SubscriptionRequest<S,? super T,? extends SubscriptionRequest.RequestOptions> request, Class<T> bodyType)	Register a new SubscriptionRequest in the container.
<S, T> Subscription	register(SubscriptionRequest<S,? super T,? extends SubscriptionRequest.RequestOptions> request, Class<T> bodyType, ErrorHandler errorHandler)	Register a new SubscriptionRequest in the container.
Subscription	register(SubscriptionRequest request, Task task)
void	remove(Subscription subscription)	Unregister a given Subscription from the container.
void	start()
void	stop()
void	stop(Runnable callback)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.data.mongodb.core.messaging.MessageListenerContainer

register

Constructor Details

DefaultMessageListenerContainer

public DefaultMessageListenerContainer(MongoTemplate template)

Create a new DefaultMessageListenerContainer.

Parameters:

template - must not be null.

DefaultMessageListenerContainer

public DefaultMessageListenerContainer(MongoTemplate template,
 Executor taskExecutor)

Create a new DefaultMessageListenerContainer running tasks via the given taskExecutor.

Parameters:

template - must not be null.

taskExecutor - must not be null.

DefaultMessageListenerContainer

public DefaultMessageListenerContainer(MongoTemplate template,
 Executor taskExecutor,
 @Nullable
 ErrorHandler errorHandler)

Create a new DefaultMessageListenerContainer running tasks via the given taskExecutor delegating errors to the given ErrorHandler.

Parameters:

template - must not be null. Used by the TaskFactory.

taskExecutor - must not be null.

errorHandler - the default ErrorHandler to be used by tasks inside the container. Can be null.

Method Details

isAutoStartup

public boolean isAutoStartup()

Specified by:

isAutoStartup in interface SmartLifecycle

stop

public void stop(Runnable callback)

Specified by:

stop in interface SmartLifecycle

start

public void start()

Specified by:

start in interface Lifecycle

stop

public void stop()

Specified by:

stop in interface Lifecycle

isRunning

public boolean isRunning()

Specified by:

isRunning in interface Lifecycle

getPhase

public int getPhase()

Specified by:

getPhase in interface Phased

Specified by:

getPhase in interface SmartLifecycle

register

public <S,
T> Subscription register(SubscriptionRequest<S,? super T,? extends SubscriptionRequest.RequestOptions> request,
 Class<T> bodyType)

Description copied from interface: MessageListenerContainer

Register a new SubscriptionRequest in the container. If the is already running the Subscription will be added and run immediately, otherwise it'll be scheduled and started once the container is actually started.

 
     MessageListenerContainer container = ...

     MessageListener<ChangeStreamDocument<Document>, Document> messageListener = (message) -> message.getBody().toJson();
     ChangeStreamRequest<Document> request = new ChangeStreamRequest<>(messageListener, () -> "collection-name");

     Subscription subscription = container.register(request, Document.class);
 
 

On Lifecycle.stop() all subscriptions are cancelled prior to shutting down the container itself.
Registering the very same SubscriptionRequest more than once simply returns the already existing Subscription.
Unless a Subscription is removed form the container, the Subscription is restarted once the container itself is restarted.
Errors during Message retrieval lead to cannelation of the underlying task.

Specified by:

register in interface MessageListenerContainer

Parameters:

request - must not be null.

bodyType - the exact target or a more concrete type of the Message.getBody().

Returns:

never null.

register

public <S,
T> Subscription register(SubscriptionRequest<S,? super T,? extends SubscriptionRequest.RequestOptions> request,
 Class<T> bodyType,
 ErrorHandler errorHandler)

Description copied from interface: MessageListenerContainer

Register a new SubscriptionRequest in the container. If the is already running the Subscription will be added and run immediately, otherwise it'll be scheduled and started once the container is actually started.

 
     MessageListenerContainer container = ...

     MessageListener<ChangeStreamDocument<Document>, Document> messageListener = (message) -> message.getBody().toJson();
     ChangeStreamRequest<Document> request = new ChangeStreamRequest<>(messageListener, () -> "collection-name");

     Subscription subscription = container.register(request, Document.class);
 
 

On Lifecycle.stop() all subscriptions are cancelled prior to shutting down the container itself.
Registering the very same SubscriptionRequest more than once simply returns the already existing Subscription.
Unless a Subscription is removed form the container, the Subscription is restarted once the container itself is restarted.
Errors during Message retrieval are delegated to the given ErrorHandler.

Specified by:

register in interface MessageListenerContainer

Parameters:

request - must not be null.

bodyType - the exact target or a more concrete type of the Message.getBody(). Must not be null.

errorHandler - the callback to invoke when retrieving the Message from the data source fails for some reason.

Returns:

never null.

lookup

public Optional<Subscription> lookup(SubscriptionRequest<?,?,?> request)

Description copied from interface: MessageListenerContainer

Lookup the given SubscriptionRequest within the container and return the associated Subscription if present.

Specified by:

lookup in interface MessageListenerContainer

Parameters:

request - must not be null.

Returns:

Optional.empty() if not set.

register

public Subscription register(SubscriptionRequest request,
 Task task)

remove

public void remove(Subscription subscription)

Description copied from interface: MessageListenerContainer

Unregister a given Subscription from the container. This prevents the Subscription to be restarted in a potential stop/start scenario.
An active subcription is cancelled prior to removal.

Specified by:

remove in interface MessageListenerContainer

Parameters:

subscription - must not be null.