org.apache.camel.impl

Class ScheduledBatchPollingConsumer

java.lang.Object

org.apache.camel.support.ServiceSupport

org.apache.camel.impl.DefaultConsumer

org.apache.camel.impl.ScheduledPollConsumer

org.apache.camel.impl.ScheduledBatchPollingConsumer

All Implemented Interfaces:

Runnable, BatchConsumer, Consumer, EndpointAware, PollingConsumerPollingStrategy, RouteAware, Service, ShutdownableService, ShutdownAware, ShutdownPrepared, StatefulService, Suspendable, SuspendableService

Direct Known Subclasses:

GenericFileConsumer

public abstract class ScheduledBatchPollingConsumer
extends ScheduledPollConsumer
implements BatchConsumer, ShutdownAware

A useful base class for any consumer which is polling batch based

Field Summary

Fields

Modifier and Type	Field and Description
protected int	maxMessagesPerPoll
protected int	pendingExchanges
protected ShutdownRunningTask	shutdownRunningTask

Fields inherited from class org.apache.camel.impl.DefaultConsumer

log

Fields inherited from class org.apache.camel.support.ServiceSupport

shutdown, shuttingdown, started, starting, stopped, stopping, suspended, suspending

Constructor Summary

Constructors

Constructor and Description
ScheduledBatchPollingConsumer(Endpoint endpoint, Processor processor)
ScheduledBatchPollingConsumer(Endpoint endpoint, Processor processor, ScheduledExecutorService executor)

Method Summary

Modifier and Type	Method and Description
boolean	deferShutdown(ShutdownRunningTask shutdownRunningTask) To defer shutdown during first phase of shutdown.
int	getMaxMessagesPerPoll() Gets the maximum number of messages as a limit to poll at each polling.
int	getPendingExchangesSize() Gets the number of pending exchanges.
boolean	isBatchAllowed() Whether processing the batch is still allowed.
void	prepareShutdown(boolean suspendOnly, boolean forced) Prepares for stop/shutdown.
protected void	processEmptyMessage() No messages to poll so send an empty message instead.
void	setMaxMessagesPerPoll(int maxMessagesPerPoll) Sets a maximum number of messages as a limit to poll at each polling.

Methods inherited from class org.apache.camel.impl.ScheduledPollConsumer

afterPoll, beforePoll, doShutdown, doStart, doStop, doSuspend, getBackoffCounter, getBackoffErrorThreshold, getBackoffIdleThreshold, getBackoffMultiplier, getDelay, getInitialDelay, getPollStrategy, getRunLoggingLevel, getScheduledExecutorService, getScheduler, getSchedulerProperties, getTimeUnit, isGreedy, isPollAllowed, isPolling, isSchedulerStarted, isSendEmptyMessageWhenIdle, isStartScheduler, isUseFixedDelay, onInit, poll, run, setBackoffErrorThreshold, setBackoffIdleThreshold, setBackoffMultiplier, setDelay, setGreedy, setInitialDelay, setPollStrategy, setRunLoggingLevel, setScheduledExecutorService, setScheduler, setSchedulerProperties, setSendEmptyMessageWhenIdle, setStartScheduler, setTimeUnit, setUseFixedDelay, startScheduler

Methods inherited from class org.apache.camel.impl.DefaultConsumer

createUoW, doneUoW, getAsyncProcessor, getEndpoint, getExceptionHandler, getProcessor, getRoute, handleException, handleException, setExceptionHandler, setRoute, toString

Methods inherited from class org.apache.camel.support.ServiceSupport

doResume, getStatus, getVersion, isRunAllowed, isStarted, isStarting, isStopped, isStopping, isStoppingOrStopped, isSuspended, isSuspending, isSuspendingOrSuspended, resume, shutdown, start, stop, suspend

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.camel.BatchConsumer

processBatch

Methods inherited from interface org.apache.camel.Service

start, stop

Methods inherited from interface org.apache.camel.EndpointAware

getEndpoint

Field Detail

shutdownRunningTask

protected volatile ShutdownRunningTask shutdownRunningTask

pendingExchanges

protected volatile int pendingExchanges

maxMessagesPerPoll

protected int maxMessagesPerPoll

Constructor Detail

ScheduledBatchPollingConsumer

public ScheduledBatchPollingConsumer(Endpoint endpoint,
                                     Processor processor)

ScheduledBatchPollingConsumer

public ScheduledBatchPollingConsumer(Endpoint endpoint,
                                     Processor processor,
                                     ScheduledExecutorService executor)

Method Detail

deferShutdown

public boolean deferShutdown(ShutdownRunningTask shutdownRunningTask)

Description copied from interface: ShutdownAware

To defer shutdown during first phase of shutdown. This allows any pending exchanges to be completed and therefore ensure a graceful shutdown without loosing messages. At the very end when there are no more inflight and pending messages the consumer could then safely be shutdown.

This is needed by SedaConsumer.

Specified by:

deferShutdown in interface ShutdownAware

Parameters:

shutdownRunningTask - the configured option for how to act when shutting down running tasks.

Returns:

true to defer shutdown to very last.

getPendingExchangesSize

public int getPendingExchangesSize()

Description copied from interface: ShutdownAware

Gets the number of pending exchanges.

Some consumers has internal queues with Exchange which are pending. For example the SedaConsumer.

Return zero to indicate no pending exchanges and therefore ready to shutdown.

Specified by:

getPendingExchangesSize in interface ShutdownAware

Returns:

number of pending exchanges

prepareShutdown

public void prepareShutdown(boolean suspendOnly,
                            boolean forced)

Description copied from interface: ShutdownPrepared

Prepares for stop/shutdown.

The ShutdownStrategy supports preparing for shutdown using two steps. First a regular preparation, where the given forced parameter will be false. And if the shutdown times out, then the ShutdownStrategy performs a more aggressive shutdown, calling this method a second time with true for the given forced parameter. For example by graceful stopping any threads or the likes.

In addition a service can also be suspended (not stopped), and when this happens the parameter suspendOnly has the value true. This can be used to prepare the service for suspension, such as marking a worker thread to skip action.

For forced shutdown, then the service is expected to aggressively shutdown any child services, such as thread pools etc. This is the last chance it has to perform such duties.

Specified by:

prepareShutdown in interface ShutdownPrepared

Parameters:

suspendOnly - true if the intention is to only suspend the service, and not stop/shutdown the service.

forced - true is forcing a more aggressive shutdown, false is for preparing to shutdown.

setMaxMessagesPerPoll

public void setMaxMessagesPerPoll(int maxMessagesPerPoll)

Description copied from interface: BatchConsumer

Sets a maximum number of messages as a limit to poll at each polling.

Can be used to limit e.g. to 100 to avoid reading thousands or more messages within the first polling at startup.

Is default unlimited, but use 0 or negative number to disable it as unlimited.

Specified by:

setMaxMessagesPerPoll in interface BatchConsumer

Parameters:

maxMessagesPerPoll - maximum messages to poll.

getMaxMessagesPerPoll

public int getMaxMessagesPerPoll()

Gets the maximum number of messages as a limit to poll at each polling.

Is default unlimited, but use 0 or negative number to disable it as unlimited.

Returns:

max messages to poll

isBatchAllowed

public boolean isBatchAllowed()

Description copied from interface: BatchConsumer

Whether processing the batch is still allowed.

This is used during shutdown to indicate whether to complete the pending exchanges or stop after the current exchange has been processed.

Specified by:

isBatchAllowed in interface BatchConsumer

Returns:

true to continue processing from the batch, or false to stop.

See Also:

ShutdownRunningTask

processEmptyMessage

protected void processEmptyMessage()
                            throws Exception

Description copied from class: ScheduledPollConsumer

No messages to poll so send an empty message instead.

Overrides:

processEmptyMessage in class ScheduledPollConsumer

Throws:

Exception - is thrown if error processing the empty message.