## org.springframework.jms.listener
Class DefaultMessageListenerContainer

    java.lang.Object
      org.springframework.jms.support.JmsAccessor
          org.springframework.jms.support.destination.JmsDestinationAccessor
              org.springframework.jms.listener.AbstractJmsListeningContainer
                  org.springframework.jms.listener.AbstractMessageListenerContainer
                      org.springframework.jms.listener.AbstractPollingMessageListenerContainer
                          org.springframework.jms.listener.DefaultMessageListenerContainer

All Implemented Interfaces:
  BeanNameAware, DisposableBean, InitializingBean, Lifecycle

Direct Known Subclasses:
  DefaultMessageListenerContainer102

    public class DefaultMessageListenerContainer

extends AbstractPollingMessageListenerContainer

Message listener container variant that uses plain JMS client API, specifically a loop of `MessageConsumer.receive()` calls that also allow for transactional reception of messages (registering them with XA transactions). Designed to work in a native JMS environment as well as in a J2EE environment, with only minimal differences in configuration.

NOTE: This class requires a JMS 1.1+ provider, because it builds on the domain-independent API. Use the `DefaultMessageListenerContainer102` subclass for a JMS 1.0.2 provider, e.g. when running on a J2EE 1.3 server.

This is a simple but nevertheless powerful form of message listener container. On startup, it obtains a fixed number of JMS Sessions to invoke the listener, and optionally allows for dynamic adaptation at runtime (up until a maximum number). Like `SimpleMessageListenerContainer`, its main advantage is its low level of runtime complexity, in particular the minimal requirements on the JMS provider: Not even the JMS ServerSessionPool facility is required. Beyond that, it is fully self-recovering in case of the broker being temporarily unavailable, and allows for stops/restarts as well as runtime changes to its configuration.

Actual MessageListener execution happens in asynchronous work units which are created through Spring's `TaskExecutor` abstraction. By default, the specified number of invoker tasks will be created on startup, according to the `"concurrentConsumers"` setting. Specify an alternative TaskExecutor to integrate with an existing thread pool facility (such as a J2EE server's), for example using a `CommonJ WorkManager`. With a native JMS setup, each of those listener threads is going to use a cached JMS Session and MessageConsumer (only refreshed in case of failure), using the JMS provider's resources as efficiently as possible.

Message reception and listener execution can automatically be wrapped in transactions through passing a Spring `PlatformTransactionManager` into the `"transactionManager"` property. This will usually be a `JtaTransactionManager` in a J2EE enviroment, in combination with a JTA-aware JMS ConnectionFactory obtained from JNDI (check your J2EE server's documentation). Note that this listener container will automatically reobtain all JMS handles for each transaction in case of an external transaction manager specified, for compatibility with all J2EE servers (in particular JBoss). This non-caching behavior can be overridden through the `"cacheLevel"` / `"cacheLevelName"` property, enforcing caching of the Connection (or also Session and MessageConsumer) even in case of an external transaction manager being involved.

Dynamic scaling of the number of concurrent invokers can be activated through specifying a `"maxConcurrentConsumers"` value that is higher than the `"concurrentConsumers"` value. Since the latter's default is 1, you can also simply specify a "maxConcurrentConsumers" of e.g. 5, which will lead to dynamic scaling up to 5 concurrent consumers in case of increasing message load, as well as dynamic shrinking back to the standard number of consumers once the load decreases. Consider adapting the `"idleTaskExecutionLimit"` setting to control the lifespan of each new task, to avoid frequent scaling up and down, in particular if the ConnectionFactory does not pool JMS Sessions and/or the TaskExecutor does not pool threads (check your configuration!). Note that dynamic scaling only really makes sense for a queue in the first place; for a topic, you will typically stick with the default number of 1 consumer, else you'd receive the same message multiple times on the same node.

It is strongly recommended to either set `"sessionTransacted"` to "true" or specify an external `"transactionManager"`. See the `AbstractMessageListenerContainer` javadoc for details on acknowledge modes and native transaction options, as well as the `AbstractPollingMessageListenerContainer` javadoc for details on configuring an external transaction manager.

Since:
  2.0
Author:
  Juergen Hoeller
See Also:
  `AbstractPollingMessageListenerContainer.setTransactionManager(org.springframework.transaction.PlatformTransactionManager)`, `setCacheLevel(int)`, `MessageConsumer.receive(long)`, `SimpleMessageListenerContainer`, `JmsMessageEndpointManager`

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.jms.listener.AbstractJmsListeningContainer
`AbstractJmsListeningContainer.SharedConnectionNotInitializedException`

Field Summary
`static int` `CACHE_AUTO` Constant that indicates automatic choice of an appropriate caching level (depending on the transaction management strategy).
`static int` `CACHE_CONNECTION` Constant that indicates to cache a shared JMS Connection.
`static int` `CACHE_CONSUMER` Constant that indicates to cache a shared JMS Connection and a JMS Session for each listener thread, as well as a JMS MessageConsumer for each listener thread.
`static int` `CACHE_NONE` Constant that indicates to cache no JMS resources at all.
`static int` `CACHE_SESSION` Constant that indicates to cache a shared JMS Connection and a JMS Session for each listener thread.
`static long` `DEFAULT_RECOVERY_INTERVAL` The default recovery interval: 5000 ms = 5 seconds.
`static String` `DEFAULT_THREAD_NAME_PREFIX` Default thread name prefix: "DefaultMessageListenerContainer-".

Fields inherited from class org.springframework.jms.listener.AbstractPollingMessageListenerContainer
`DEFAULT_RECEIVE_TIMEOUT`

Fields inherited from class org.springframework.jms.listener.AbstractJmsListeningContainer
`lifecycleMonitor, sharedConnectionMonitor`

Fields inherited from class org.springframework.jms.support.JmsAccessor
`logger`

Constructor Summary
`DefaultMessageListenerContainer()`

Method Summary
`protected TaskExecutor` `createDefaultTaskExecutor()` Create a default TaskExecutor.
`protected void` `doInitialize()` Creates the specified number of concurrent consumers, in the form of a JMS Session plus associated MessageConsumer running in a separate thread.
`protected void` `doRescheduleTask(Object task)` Re-executes the given task via this listener container's TaskExecutor.
`protected void` `doShutdown()` Destroy the registered JMS Sessions and associated MessageConsumers.
`protected void` `establishSharedConnection()` Overridden to accept a failure in the initial setup - leaving it up to the asynchronous invokers to establish the shared Connection on first access.
`int` `getActiveConsumerCount()` Return the number of currently active consumers.
`int` `getCacheLevel()` Return the level of caching that this listener container is allowed to apply.
`int` `getConcurrentConsumers()` Return the "concurrentConsumer" setting.
`int` `getIdleTaskExecutionLimit()` Return the limit for idle executions of a receive task.
`int` `getMaxConcurrentConsumers()` Return the "maxConcurrentConsumer" setting.
`int` `getMaxMessagesPerTask()` Return the maximum number of messages to process in one task.
`int` `getScheduledConsumerCount()` Return the number of currently scheduled consumers.
`protected void` `handleListenerSetupFailure(Throwable ex, boolean alreadyRecovered)` Handle the given exception that arose during setup of a listener.
`void` `initialize()` Initialize this container.
`protected void` `messageReceived(Object invoker, Session session)` Tries scheduling a new invoker, since we know messages are coming in...
`protected void` `noMessageReceived(Object invoker, Session session)` Marks the affected invoker as idle.
`protected void` `recoverAfterListenerSetupFailure()` Recover this listener container after a listener failed to set itself up, for example reestablishing the underlying Connection.
`protected void` `refreshConnectionUntilSuccessful()` Refresh the underlying Connection, not returning before an attempt has been successful.
`protected void` `refreshDestination()` Refresh the JMS destination that this listener container operates on.
`protected void` `scheduleNewInvokerIfAppropriate()` Schedule a new invoker, increasing the total number of scheduled invokers for this listener container, but only if the specified "maxConcurrentConsumers" limit has not been reached yet, and only if this listener container does not currently have idle invokers that are waiting for new messages already.
`void` `setCacheLevel(int cacheLevel)` Specify the level of caching that this listener container is allowed to apply.
`void` `setCacheLevelName(String constantName)` Specify the level of caching that this listener container is allowed to apply, in the form of the name of the corresponding constant: e.g.
`void` `setConcurrentConsumers(int concurrentConsumers)` Specify the number of concurrent consumers to create.
`void` `setIdleTaskExecutionLimit(int idleTaskExecutionLimit)` Specify the limit for idle executions of a receive task, not having received any message within its execution.
`void` `setMaxConcurrentConsumers(int maxConcurrentConsumers)` Specify the maximum number of concurrent consumers to create.
`void` `setMaxMessagesPerTask(int maxMessagesPerTask)` Specify the maximum number of messages to process in one task.
`void` `setRecoveryInterval(long recoveryInterval)` Specify the interval between recovery attempts, in milliseconds.
`void` `setTaskExecutor(TaskExecutor taskExecutor)` Set the Spring TaskExecutor to use for running the listener threads.
`protected boolean` `sharedConnectionEnabled()` Use a shared JMS Connection depending on the "cacheLevel" setting.
`protected void` `sleepInbetweenRecoveryAttempts()` Sleep according to the specified recovery interval.
`void` `start()` Overridden to reset the stop callback, if any.
`protected void` `startSharedConnection()` This implementations proceeds even after an exception thrown from `Connection.start()`, relying on listeners to perform appropriate recovery.
`void` `stop(Runnable callback)` Stop this listener container, invoking the specific callback once all listener processing has actually stopped.
`protected void` `stopSharedConnection()` This implementations proceeds even after an exception thrown from `Connection.stop()`, relying on listeners to perform appropriate recovery after a restart.
`protected void` `validateConfiguration()` Validate the configuration of this container.

Methods inherited from class org.springframework.jms.listener.AbstractPollingMessageListenerContainer
`createConsumer, createListenerConsumer, doReceiveAndExecute, getConnection, getSession, getTransactionManager, isPubSubNoLocal, isSessionLocallyTransacted, receiveAndExecute, receiveMessage, setPubSubNoLocal, setReceiveTimeout, setSessionTransacted, setTransactionManager, setTransactionName, setTransactionTimeout`

Methods inherited from class org.springframework.jms.listener.AbstractMessageListenerContainer

`checkMessageListener, commitIfNecessary, doExecuteListener, doInvokeListener, doInvokeListener, executeListener, getDefaultSubscriptionName, getDestination, getDestinationDescription, getDestinationName, getDurableSubscriptionName, getExceptionListener, getMessageListener, getMessageSelector, handleListenerException, invokeExceptionListener, invokeListener, isAcceptMessagesWhileStopping, isExposeListenerSession, isSubscriptionDurable, rollbackIfNecessary, rollbackOnExceptionIfNecessary, setAcceptMessagesWhileStopping, setDestination, setDestinationName, setDurableSubscriptionName, setExceptionListener, setExposeListenerSession, setMessageListener, setMessageSelector, setSubscriptionDurable`

Methods inherited from class org.springframework.jms.listener.AbstractJmsListeningContainer
`afterPropertiesSet, createSharedConnection, destroy, doStart, doStop, getBeanName, getClientId, getPausedTaskCount, getSharedConnection, isActive, isRunning, logRejectedTask, prepareSharedConnection, refreshSharedConnection, rescheduleTaskIfNecessary, resumePausedTasks, runningAllowed, setAutoStartup, setBeanName, setClientId, shutdown, stop`

Methods inherited from class org.springframework.jms.support.destination.JmsDestinationAccessor
`getDestinationResolver, isPubSubDomain, resolveDestinationName, setDestinationResolver, setPubSubDomain`

Methods inherited from class org.springframework.jms.support.JmsAccessor
`convertJmsAccessException, createConnection, createSession, getConnectionFactory, getSessionAcknowledgeMode, isClientAcknowledge, isSessionTransacted, setConnectionFactory, setSessionAcknowledgeMode, setSessionAcknowledgeModeName`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Methods inherited from interface org.springframework.beans.factory.BeanNameAware
`setBeanName`

Field Detail

### DEFAULT_THREAD_NAME_PREFIX

    public static final String DEFAULT_THREAD_NAME_PREFIX

  Default thread name prefix: "DefaultMessageListenerContainer-".

### DEFAULT_RECOVERY_INTERVAL

    public static final long DEFAULT_RECOVERY_INTERVAL

  The default recovery interval: 5000 ms = 5 seconds.

  See Also:
    Constant Field Values

### CACHE_NONE

    public static final int CACHE_NONE

  Constant that indicates to cache no JMS resources at all.

  See Also:
    `setCacheLevel(int)`, Constant Field Values

### CACHE_CONNECTION

    public static final int CACHE_CONNECTION

  Constant that indicates to cache a shared JMS Connection.

  See Also:
    `setCacheLevel(int)`, Constant Field Values

### CACHE_SESSION

    public static final int CACHE_SESSION

  Constant that indicates to cache a shared JMS Connection and a JMS Session for each listener thread.

  See Also:
    `setCacheLevel(int)`, Constant Field Values

### CACHE_CONSUMER

    public static final int CACHE_CONSUMER

  Constant that indicates to cache a shared JMS Connection and a JMS Session for each listener thread, as well as a JMS MessageConsumer for each listener thread.

  See Also:
    `setCacheLevel(int)`, Constant Field Values

### CACHE_AUTO

    public static final int CACHE_AUTO

  Constant that indicates automatic choice of an appropriate caching level (depending on the transaction management strategy).

  See Also:
    `setCacheLevel(int)`, Constant Field Values

Constructor Detail

### DefaultMessageListenerContainer

    public DefaultMessageListenerContainer()

Method Detail

### setTaskExecutor

    public void setTaskExecutor(TaskExecutor taskExecutor)

  Set the Spring TaskExecutor to use for running the listener threads.

  Default is a `SimpleAsyncTaskExecutor`, starting up a number of new threads, according to the specified number of concurrent consumers.

  Specify an alternative TaskExecutor for integration with an existing thread pool. Note that this really only adds value if the threads are managed in a specific fashion, for example within a J2EE environment. A plain thread pool does not add much value, as this listener container will occupy a number of threads for its entire lifetime.

  See Also:
    `setConcurrentConsumers(int)`, `SimpleAsyncTaskExecutor`, `WorkManagerTaskExecutor`

### setRecoveryInterval

    public void setRecoveryInterval(long recoveryInterval)

  Specify the interval between recovery attempts, in milliseconds. The default is 5000 ms, that is, 5 seconds.

  See Also:
    `handleListenerSetupFailure(java.lang.Throwable, boolean)`

### setCacheLevelName

    public void setCacheLevelName(String constantName)
                           throws IllegalArgumentException

  Specify the level of caching that this listener container is allowed to apply, in the form of the name of the corresponding constant: e.g. "CACHE_CONNECTION".

  Throws:
    `IllegalArgumentException`
  See Also:
    `setCacheLevel(int)`

### setCacheLevel

    public void setCacheLevel(int cacheLevel)

  Specify the level of caching that this listener container is allowed to apply.

  Default is CACHE_NONE if an external transaction manager has been specified (to reobtain all resources freshly within the scope of the external transaction), and CACHE_CONSUMER else (operating with local JMS resources).

  Some J2EE servers only register their JMS resources with an ongoing XA transaction in case of a freshly obtained JMS Connection and Session, which is why this listener container does by default not cache any of those. However, if you want to optimize for a specific server, consider switching this setting to at least CACHE_CONNECTION or CACHE_SESSION even in conjunction with an external transaction manager.

  Currently known servers that absolutely require CACHE_NONE for XA transaction processing: JBoss 4. For any others, consider raising the cache level.

  See Also:
    `CACHE_NONE`, `CACHE_CONNECTION`, `CACHE_SESSION`, `CACHE_CONSUMER`, `setCacheLevelName(java.lang.String)`, `AbstractPollingMessageListenerContainer.setTransactionManager(org.springframework.transaction.PlatformTransactionManager)`

### getCacheLevel

    public int getCacheLevel()

  Return the level of caching that this listener container is allowed to apply.

### setConcurrentConsumers

    public void setConcurrentConsumers(int concurrentConsumers)

  Specify the number of concurrent consumers to create. Default is 1.

  Specifying a higher value for this setting will increase the standard level of scheduled concurrent consumers at runtime: This is effectively the minimum number of concurrent consumers which will be scheduled at any given time. This is a static setting; for dynamic scaling, consider specifying the "maxConcurrentConsumers" setting instead.

  Raising the number of concurrent consumers is recommendable in order to scale the consumption of messages coming in from a queue. However, note that any ordering guarantees are lost once multiple consumers are registered. In general, stick with 1 consumer for low-volume queues.

  Do not raise the number of concurrent consumers for a topic. This would lead to concurrent consumption of the same message, which is hardly ever desirable.

  This setting can be modified at runtime, for example through JMX.

  See Also:
    `setMaxConcurrentConsumers(int)`

### getConcurrentConsumers

    public final int getConcurrentConsumers()

  Return the "concurrentConsumer" setting.

  This returns the currently configured "concurrentConsumers" value; the number of currently scheduled/active consumers might differ.

  See Also:
    `getScheduledConsumerCount()`, `getActiveConsumerCount()`

### setMaxConcurrentConsumers

    public void setMaxConcurrentConsumers(int maxConcurrentConsumers)

  Specify the maximum number of concurrent consumers to create. Default is 1.

  If this setting is higher than "concurrentConsumers", the listener container will dynamically schedule new consumers at runtime, provided that enough incoming messages are encountered. Once the load goes down again, the number of consumers will be reduced to the standard level ("concurrentConsumers") again.

  Raising the number of concurrent consumers is recommendable in order to scale the consumption of messages coming in from a queue. However, note that any ordering guarantees are lost once multiple consumers are registered. In general, stick with 1 consumer for low-volume queues.

  Do not raise the number of concurrent consumers for a topic. This would lead to concurrent consumption of the same message, which is hardly ever desirable.

  This setting can be modified at runtime, for example through JMX.

  See Also:
    `setConcurrentConsumers(int)`

### getMaxConcurrentConsumers

    public final int getMaxConcurrentConsumers()

  Return the "maxConcurrentConsumer" setting.

  This returns the currently configured "maxConcurrentConsumers" value; the number of currently scheduled/active consumers might differ.

  See Also:
    `getScheduledConsumerCount()`, `getActiveConsumerCount()`

### setMaxMessagesPerTask

    public void setMaxMessagesPerTask(int maxMessagesPerTask)

  Specify the maximum number of messages to process in one task. More concretely, this limits the number of message reception attempts per task, which includes receive iterations that did not actually pick up a message until they hit their timeout (see the `"receiveTimeout"` property).

  Default is unlimited (-1) in case of a standard TaskExecutor, reusing the original invoker threads until shutdown (at the expense of limited dynamic scheduling).

  In case of a SchedulingTaskExecutor indicating a preference for short-lived tasks, the default is 10 instead. Specify a number of 10 to 100 messages to balance between rather long-lived and rather short-lived tasks here.

  Long-lived tasks avoid frequent thread context switches through sticking with the same thread all the way through, while short-lived tasks allow thread pools to control the scheduling. Hence, thread pools will usually prefer short-lived tasks.

  This setting can be modified at runtime, for example through JMX.

  See Also:
    `setTaskExecutor(org.springframework.core.task.TaskExecutor)`, `AbstractPollingMessageListenerContainer.setReceiveTimeout(long)`, `SchedulingTaskExecutor.prefersShortLivedTasks()`

### getMaxMessagesPerTask

    public int getMaxMessagesPerTask()

  Return the maximum number of messages to process in one task.

### setIdleTaskExecutionLimit

    public void setIdleTaskExecutionLimit(int idleTaskExecutionLimit)

  Specify the limit for idle executions of a receive task, not having received any message within its execution. If this limit is reached, the task will shut down and leave receiving to other executing tasks.

  Default is 1, closing idle resources early once a task didn't receive a message. This applies to dynamic scheduling only; see the `"maxConcurrentConsumers"` setting. The minimum number of consumers (see `"concurrentConsumers"`) will be kept around until shutdown in any case.

  Within each task execution, a number of message reception attempts (according to the "maxMessagesPerTask" setting) will each wait for an incoming message (according to the "receiveTimeout" setting). If all of those receive attempts in a given task return without a message, the task is considered idle with respect to received messages. Such a task may still be rescheduled; however, once it reached the specified "idleTaskExecutionLimit", it will shut down (in case of dynamic scaling).

  Raise this limit if you encounter too frequent scaling up and down. With this limit being higher, an idle consumer will be kept around longer, avoiding the restart of a consumer once a new load of messages comes in. Alternatively, specify a higher "maxMessagesPerTask" and/or "receiveTimeout" value, which will also lead to idle consumers being kept around for a longer time (while also increasing the average execution time of each scheduled task).

  This setting can be modified at runtime, for example through JMX.

  See Also:
    `setMaxMessagesPerTask(int)`, `AbstractPollingMessageListenerContainer.setReceiveTimeout(long)`

### getIdleTaskExecutionLimit

    public int getIdleTaskExecutionLimit()

  Return the limit for idle executions of a receive task.

### validateConfiguration

    protected void validateConfiguration()

  Description copied from class: `AbstractJmsListeningContainer`
  Validate the configuration of this container.

  The default implementation is empty. To be overridden in subclasses.

  Overrides:
    `validateConfiguration` in class `AbstractMessageListenerContainer`

### initialize

    public void initialize()

  Description copied from class: `AbstractJmsListeningContainer`
  Initialize this container.

  Creates a JMS Connection, starts the `Connection` (if `"autoStartup"` hasn't been turned off), and calls `AbstractJmsListeningContainer.doInitialize()`.

  Overrides:
    `initialize` in class `AbstractPollingMessageListenerContainer`

### doInitialize

    protected void doInitialize()
                         throws JMSException

  Creates the specified number of concurrent consumers, in the form of a JMS Session plus associated MessageConsumer running in a separate thread.

  Specified by:
    `doInitialize` in class `AbstractJmsListeningContainer`
  Throws:
    `JMSException` - if registration failed
  See Also:
    `scheduleNewInvoker()`, `setTaskExecutor(org.springframework.core.task.TaskExecutor)`

### doShutdown

    protected void doShutdown()
                       throws JMSException

  Destroy the registered JMS Sessions and associated MessageConsumers.

  Specified by:
    `doShutdown` in class `AbstractJmsListeningContainer`
  Throws:
    `JMSException` - if shutdown failed
  See Also:
    `AbstractJmsListeningContainer.shutdown()`

### start

    public void start()
               throws JmsException

  Overridden to reset the stop callback, if any.

  Specified by:
    `start` in interface `Lifecycle`
  Overrides:
    `start` in class `AbstractJmsListeningContainer`
  Throws:
    `JmsException` - if starting failed
  See Also:
    `AbstractJmsListeningContainer.doStart()`

### stop

    public void stop(Runnable callback)
              throws JmsException

  Stop this listener container, invoking the specific callback once all listener processing has actually stopped.

  Note: Further `stop(runnable)` calls (before processing has actually stopped) will override the specified callback. Only the latest specified callback will be invoked.

  If a subsequent `start()` call restarts the listener container before it has fully stopped, the callback will not get invoked at all.

  Parameters:
    `callback` - the callback to invoke once listener processing has fully stopped
  Throws:
    `JmsException` - if stopping failed
  See Also:
    `AbstractJmsListeningContainer.stop()`

### getScheduledConsumerCount

    public final int getScheduledConsumerCount()

  Return the number of currently scheduled consumers.

  This number will always be inbetween "concurrentConsumers" and "maxConcurrentConsumers", but might be higher than "activeConsumerCount" (in case of some consumers being scheduled but not executed at the moment).

  See Also:
    `getConcurrentConsumers()`, `getMaxConcurrentConsumers()`, `getActiveConsumerCount()`

### getActiveConsumerCount

    public final int getActiveConsumerCount()

  Return the number of currently active consumers.

  This number will always be inbetween "concurrentConsumers" and "maxConcurrentConsumers", but might be lower than "scheduledConsumerCount". (in case of some consumers being scheduled but not executed at the moment).

  See Also:
    `getConcurrentConsumers()`, `getMaxConcurrentConsumers()`, `getActiveConsumerCount()`

### createDefaultTaskExecutor

    protected TaskExecutor createDefaultTaskExecutor()

  Create a default TaskExecutor. Called if no explicit TaskExecutor has been specified.

  The default implementation builds a `SimpleAsyncTaskExecutor` with the specified bean name (or the class name, if no bean name specified) as thread name prefix.

  See Also:
    `SimpleAsyncTaskExecutor.SimpleAsyncTaskExecutor(String)`

### sharedConnectionEnabled

    protected final boolean sharedConnectionEnabled()

  Use a shared JMS Connection depending on the "cacheLevel" setting.

  Specified by:
    `sharedConnectionEnabled` in class `AbstractJmsListeningContainer`
  See Also:
    `setCacheLevel(int)`, `CACHE_CONNECTION`

### doRescheduleTask

    protected void doRescheduleTask(Object task)

  Re-executes the given task via this listener container's TaskExecutor.

  Overrides:
    `doRescheduleTask` in class `AbstractJmsListeningContainer`
  Parameters:
    `task` - the task object to reschedule
  See Also:
    `setTaskExecutor(org.springframework.core.task.TaskExecutor)`

### messageReceived

    protected void messageReceived(Object invoker,
                                   Session session)

  Tries scheduling a new invoker, since we know messages are coming in...

  Overrides:
    `messageReceived` in class `AbstractPollingMessageListenerContainer`
  Parameters:
    `invoker` - the invoker object (passed through)
    `session` - the receiving JMS Session
  See Also:
    `scheduleNewInvokerIfAppropriate()`

### noMessageReceived

    protected void noMessageReceived(Object invoker,
                                     Session session)

  Marks the affected invoker as idle.

  Overrides:
    `noMessageReceived` in class `AbstractPollingMessageListenerContainer`
  Parameters:
    `invoker` - the invoker object (passed through)
    `session` - the receiving JMS Session

### scheduleNewInvokerIfAppropriate

    protected void scheduleNewInvokerIfAppropriate()

  Schedule a new invoker, increasing the total number of scheduled invokers for this listener container, but only if the specified "maxConcurrentConsumers" limit has not been reached yet, and only if this listener container does not currently have idle invokers that are waiting for new messages already.

  Called once a message has been received, to scale up while processing the message in the invoker that originally received it.

  See Also:
    `setTaskExecutor(org.springframework.core.task.TaskExecutor)`, `getMaxConcurrentConsumers()`

### establishSharedConnection

    protected void establishSharedConnection()

  Overridden to accept a failure in the initial setup - leaving it up to the asynchronous invokers to establish the shared Connection on first access.

  Overrides:
    `establishSharedConnection` in class `AbstractJmsListeningContainer`
  See Also:
    `refreshConnectionUntilSuccessful()`

### startSharedConnection

    protected void startSharedConnection()

  This implementations proceeds even after an exception thrown from `Connection.start()`, relying on listeners to perform appropriate recovery.

  Overrides:
    `startSharedConnection` in class `AbstractJmsListeningContainer`
  See Also:
    `Connection.start()`

### stopSharedConnection

    protected void stopSharedConnection()

  This implementations proceeds even after an exception thrown from `Connection.stop()`, relying on listeners to perform appropriate recovery after a restart.

  Overrides:
    `stopSharedConnection` in class `AbstractJmsListeningContainer`
  See Also:
    `Connection.start()`

### handleListenerSetupFailure

    protected void handleListenerSetupFailure(Throwable ex,
                                              boolean alreadyRecovered)

  Handle the given exception that arose during setup of a listener. Called for every such exception in every concurrent listener.

  The default implementation logs the exception at error level if not recovered yet, and at debug level if already recovered. Can be overridden in subclasses.

  Parameters:
    `ex` - the exception to handle
    `alreadyRecovered` - whether a previously executing listener already recovered from the present listener setup failure (this usually indicates a follow-up failure than can be ignored other than for debug log purposes)
  See Also:
    `recoverAfterListenerSetupFailure()`

### recoverAfterListenerSetupFailure

    protected void recoverAfterListenerSetupFailure()

  Recover this listener container after a listener failed to set itself up, for example reestablishing the underlying Connection.

  The default implementation delegates to DefaultMessageListenerContainer's recovery-capable `refreshConnectionUntilSuccessful()` method, which will try to re-establish a Connection to the JMS provider both for the shared and the non-shared Connection case.

  See Also:
    `refreshConnectionUntilSuccessful()`, `refreshDestination()`

### refreshConnectionUntilSuccessful

    protected void refreshConnectionUntilSuccessful()

  Refresh the underlying Connection, not returning before an attempt has been successful. Called in case of a shared Connection as well as without shared Connection, so either needs to operate on the shared Connection or on a temporary Connection that just gets established for validation purposes.

  The default implementation retries until it successfully established a Connection, for as long as this message listener container is active. Applies the specified recovery interval between retries.

  See Also:
    `setRecoveryInterval(long)`

### refreshDestination

    protected void refreshDestination()

  Refresh the JMS destination that this listener container operates on.

  Called after listener setup failure, assuming that a cached Destination object might have become invalid (a typical case on WebLogic JMS).

  The default implementation removes the destination from a DestinationResolver's cache, in case of a CachingDestinationResolver.

  See Also:
    `AbstractMessageListenerContainer.setDestinationName(java.lang.String)`, `CachingDestinationResolver`

### sleepInbetweenRecoveryAttempts

    protected void sleepInbetweenRecoveryAttempts()

  Sleep according to the specified recovery interval. Called inbetween recovery attempts.

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