org.jboss.dna.repository.sequencers
Class SequencingService

java.lang.Object
  org.jboss.dna.repository.sequencers.SequencingService

All Implemented Interfaces:

NodeChangeListener, AdministeredService

public class SequencingService
extends Object
implements AdministeredService, NodeChangeListener

A sequencing system is used to monitor changes in the content of JCR repositories and to sequence the content to extract or to generate structured information.

Author:

Randall Hauch

Nested Class Summary

protected class	SequencingService.Administrator The administrative component for this service.
protected class	SequencingService.Context
protected static class	SequencingService.DefaultNodeFilter The default filter implementation, which accepts only new nodes or nodes that have new or changed properties.
protected static class	SequencingService.DefaultSelector The default SequencingService.Selector implementation that selects every sequencer every time it's called, regardless of the node (or logger) supplied.
static interface	SequencingService.NodeFilter Interface used to determine whether a NodeChange should be processed.
static interface	SequencingService.Selector Interface used to select the set of Sequencer instances that should be run.
protected class	SequencingService.SequencerCall
class	SequencingService.Statistics The statistics for the system.

Field Summary

protected static org.jboss.dna.common.component.ClassLoaderFactory	DEFAULT_CLASSLOADER_FACTORY Class loader factory instance that always returns the current thread's context class loader (if not null) or component library's class loader.
static SequencingService.NodeFilter	DEFAULT_NODE_FILTER The default SequencingService.NodeFilter that accepts new nodes or nodes that have new/changed properties.
static SequencingService.Selector	DEFAULT_SEQUENCER_SELECTOR The default SequencingService.Selector that considers every Sequencer to be used for every node.

Constructor Summary

SequencingService()
Create a new sequencing system, configured with no sequencers and not monitoring any workspaces.

Method Summary

boolean	addSequencer(SequencerConfig config) Add the configuration for a sequencer, or update any existing one that represents the same configuration
protected ExecutorService	createDefaultExecutorService() Override this method to creates a different kind of default executor service.
protected boolean	doAwaitTermination(long timeout, TimeUnit unit)
ServiceAdministrator	getAdministrator() Return the administrative component for this service.
JcrExecutionContext	getExecutionContext()
ExecutorService	getExecutorService() Get the executor service used to run the sequencers.
SequencingService.NodeFilter	getNodeFilter() Get the node filter used by this system.
protected org.jboss.dna.common.component.ComponentLibrary<Sequencer,SequencerConfig>	getSequencerLibrary()
SequencingService.Selector	getSequencerSelector() Get the sequencing selector used by this system.
SequencingService.Statistics	getStatistics() Get the statistics for this system.
protected boolean	isServiceTerminated()
void	onNodeChanges(NodeChanges changes)
protected void	processChangedNode(NodeChange changedNode) Do the work of processing by sequencing the node.
boolean	removeSequencer(SequencerConfig config) Remove the configuration for a sequencer.
void	setExecutionContext(JcrExecutionContext executionContext)
void	setExecutorService(ExecutorService executorService) Set the executor service that should be used by this system.
void	setNodeFilter(SequencingService.NodeFilter nodeFilter) Set the filter that checks which nodes are to be sequenced, or null if the default node filter should be used.
void	setSequencerSelector(SequencingService.Selector sequencerSelector) Set the sequencer selector, or null if the default sequencer selector should be used.
protected void	shutdownService()
protected void	startService()
boolean	updateSequencer(SequencerConfig config) Update the configuration for a sequencer, or add it if there is no matching configuration.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SEQUENCER_SELECTOR

public static final SequencingService.Selector DEFAULT_SEQUENCER_SELECTOR

The default SequencingService.Selector that considers every Sequencer to be used for every node.

See Also:

setSequencerSelector(org.jboss.dna.repository.sequencers.SequencingService.Selector)

DEFAULT_NODE_FILTER

public static final SequencingService.NodeFilter DEFAULT_NODE_FILTER

The default SequencingService.NodeFilter that accepts new nodes or nodes that have new/changed properties.

See Also:

setSequencerSelector(org.jboss.dna.repository.sequencers.SequencingService.Selector)

DEFAULT_CLASSLOADER_FACTORY

protected static final org.jboss.dna.common.component.ClassLoaderFactory DEFAULT_CLASSLOADER_FACTORY

Class loader factory instance that always returns the current thread's context class loader (if not null) or component library's class loader.

Constructor Detail

SequencingService

public SequencingService()

Create a new sequencing system, configured with no sequencers and not monitoring any workspaces. Upon construction, the system is paused and must be configured and then started.

Method Detail

getAdministrator

public ServiceAdministrator getAdministrator()

Return the administrative component for this service.

Specified by:

getAdministrator in interface AdministeredService

Returns:

the administrative component; never null

getStatistics

public SequencingService.Statistics getStatistics()

Get the statistics for this system.

Returns:

statistics

getSequencerLibrary

protected org.jboss.dna.common.component.ComponentLibrary<Sequencer,SequencerConfig> getSequencerLibrary()

Returns:

sequencerLibrary

addSequencer

public boolean addSequencer(SequencerConfig config)

Add the configuration for a sequencer, or update any existing one that represents the same configuration

Parameters:

config - the new configuration

Returns:

true if the sequencer was added, or false if there already was an existing and unchanged sequencer configuration

Throws:

IllegalArgumentException - if config is null

See Also:

updateSequencer(SequencerConfig), removeSequencer(SequencerConfig)

updateSequencer

public boolean updateSequencer(SequencerConfig config)

Update the configuration for a sequencer, or add it if there is no matching configuration.

Parameters:

config - the updated (or new) configuration

Returns:

true if the sequencer was updated, or false if there already was an existing and unchanged sequencer configuration

Throws:

IllegalArgumentException - if config is null

See Also:

addSequencer(SequencerConfig), removeSequencer(SequencerConfig)

removeSequencer

public boolean removeSequencer(SequencerConfig config)

Remove the configuration for a sequencer.

Parameters:

config - the configuration to be removed

Returns:

true if the sequencer was removed, or false if there was no existing sequencer

Throws:

IllegalArgumentException - if config is null

See Also:

addSequencer(SequencerConfig), updateSequencer(SequencerConfig)

getExecutionContext

public JcrExecutionContext getExecutionContext()

Returns:

executionContext

setExecutionContext

public void setExecutionContext(JcrExecutionContext executionContext)

Parameters:

executionContext - Sets executionContext to the specified value.

getExecutorService

public ExecutorService getExecutorService()

Get the executor service used to run the sequencers.

Returns:

the executor service

See Also:

setExecutorService(ExecutorService)

setExecutorService

public void setExecutorService(ExecutorService executorService)

Set the executor service that should be used by this system. By default, the system is set up with a executor that uses a single thread.

Parameters:

executorService - the executor service

See Also:

getExecutorService(), Executors.newCachedThreadPool(), Executors.newCachedThreadPool(java.util.concurrent.ThreadFactory), Executors.newFixedThreadPool(int), Executors.newFixedThreadPool(int, java.util.concurrent.ThreadFactory), Executors.newScheduledThreadPool(int), Executors.newScheduledThreadPool(int, java.util.concurrent.ThreadFactory), Executors.newSingleThreadExecutor(), Executors.newSingleThreadExecutor(java.util.concurrent.ThreadFactory), Executors.newSingleThreadScheduledExecutor(), Executors.newSingleThreadScheduledExecutor(java.util.concurrent.ThreadFactory)

createDefaultExecutorService

protected ExecutorService createDefaultExecutorService()

Override this method to creates a different kind of default executor service. This method is called when the system is started without an executor service being set.

This method creates a single-threaded executor.

Returns:

the executor service

startService

protected void startService()

shutdownService

protected void shutdownService()

isServiceTerminated

protected boolean isServiceTerminated()

doAwaitTermination

protected boolean doAwaitTermination(long timeout,
                                     TimeUnit unit)
                              throws InterruptedException

Throws:

InterruptedException

getSequencerSelector

public SequencingService.Selector getSequencerSelector()

Get the sequencing selector used by this system.

Returns:

the sequencing selector

setSequencerSelector

public void setSequencerSelector(SequencingService.Selector sequencerSelector)

Set the sequencer selector, or null if the default sequencer selector should be used.

Parameters:

sequencerSelector - the selector

getNodeFilter

public SequencingService.NodeFilter getNodeFilter()

Get the node filter used by this system.

Returns:

the node filter

setNodeFilter

public void setNodeFilter(SequencingService.NodeFilter nodeFilter)

Set the filter that checks which nodes are to be sequenced, or null if the default node filter should be used.

Parameters:

nodeFilter - the new node filter

onNodeChanges

public void onNodeChanges(NodeChanges changes)

Specified by:

onNodeChanges in interface NodeChangeListener

processChangedNode

protected void processChangedNode(NodeChange changedNode)

Do the work of processing by sequencing the node. This method is called by the executor service when it performs it's work on the enqueued NodeChange runnable objects.

Parameters:

changedNode - the node to be processed.