org.jboss.system
Class BarrierController

java.lang.Object
  org.jboss.mx.util.JBossNotificationBroadcasterSupport
      org.jboss.system.ServiceMBeanSupport
          org.jboss.system.ListenerServiceMBeanSupport
              org.jboss.system.BarrierController

All Implemented Interfaces:

EventListener, javax.management.MBeanRegistration, javax.management.NotificationBroadcaster, javax.management.NotificationEmitter, javax.management.NotificationListener, BarrierControllerMBean, ListenerServiceMBean, Service, ServiceMBean

public class BarrierController
extends ListenerServiceMBeanSupport
implements BarrierControllerMBean

BarrierController service. A service that controls the lifecycle of a secondary mbean (the BarrierMbean) that can be used as a dependency for other services. Starting and stopping the barrier mbean (and as a result all services depending on it) is performed by listening for any kind of JMX notification. In particular we use the handback object of a notification subscription to qualify the start and stop signals. Manual control of the barrier is also supported through startBarrier()/stopBarrier() methods. You may subclass BarrierController and override enableOnStartup() to apply complex logic in deciding whether to initially start the barrier (e.g. query some other mbean).

Version:

$Revision: 1.2.4.3 $

Author:

Dimitris Andreadis, Scott.Stark@jboss.org

Nested Class Summary

static class	BarrierController.Barrier The controlled barrier MBean class
static interface	BarrierController.BarrierMBean The controlled barrier MBean interface

Nested classes/interfaces inherited from class org.jboss.system.ListenerServiceMBeanSupport

ListenerServiceMBeanSupport.SubscriptionInfo

Field Summary

protected BarrierController.Barrier

barrier The controlled Barrier

Fields inherited from class org.jboss.system.ServiceMBeanSupport

log, server, SERVICE_CONTROLLER_SIG, serviceName

Fields inherited from interface org.jboss.system.BarrierControllerMBean

OBJECT_NAME

Fields inherited from interface org.jboss.system.ListenerServiceMBean

SL_FILTER_ELEMENT, SL_FILTER_FACTORY_ATTRIBUTE, SL_MBEAN_ELEMENT, SL_MBEAN_HANDBACK_ATTRIBUTE, SL_MBEAN_NAME_ATTRIBUTE, SL_NOTIFICATION_ELEMENT, SL_NOTIFICATION_TYPE_ATTRIBUTE, SL_ROOT_ELEMENT

Fields inherited from interface org.jboss.system.ServiceMBean

CREATE_EVENT, CREATED, DESTROY_EVENT, DESTROYED, FAILED, REGISTERED, START_EVENT, STARTED, STARTING, states, STOP_EVENT, STOPPED, STOPPING, UNREGISTERED

Constructor Summary

BarrierController()
Default CTOR

Method Summary

protected void	createService() Sub-classes should override this method to provide custum 'create' logic.
protected void	destroyService() Sub-classes should override this method to provide custum 'destroy' logic.
protected Boolean	enableOnStartup() Override this method to apply complex logic whether to start the Barrier service upon startup or not.
Boolean	getBarrierEnabledOnStartup() The initial state of the barrier.
javax.management.ObjectName	getBarrierObjectName() The controlled barrier ObjectName.
String	getBarrierStateString() The controlled barrier StateString.
Boolean	getDynamicSubscriptions() The ability to dynamically subscribe for notifications.
String	getStartBarrierHandback() The notification subscription handback string that starts the barrier.
String	getStopBarrierHandback() The notification subscription handback string that stops the barrier.
void	handleNotification2(javax.management.Notification n, Object handback) Base on the handback object the decision for starting/stopping the barrier
void	setBarrierEnabledOnStartup(Boolean enableOnStartup) The initial state of the barrier.
void	setBarrierObjectName(javax.management.ObjectName barrierName) The controlled barrier ObjectName.
void	setDynamicSubscriptions(Boolean dynamicSubscriptions) The ability to dynamically subscribe for notifications.
void	setStartBarrierHandback(String startHandback) The notification subscription handback string that starts the barrier.
void	setStopBarrierHandback(String stopHandback) The notification subscription handback string that stops the barrier.
void	startBarrier() Manually start the controlled barrier
void	stopBarrier() Manually stop the controlled barrier

Methods inherited from class org.jboss.system.ListenerServiceMBeanSupport

handleNotification, setSubscriptionList, subscribe, subscribe, subscribe, unsubscribe

Methods inherited from class org.jboss.system.ServiceMBeanSupport

create, destroy, getDeploymentInfo, getLog, getName, getNextNotificationSequenceNumber, getObjectName, getServer, getServiceName, getState, getStateString, jbossInternalCreate, jbossInternalDescription, jbossInternalDestroy, jbossInternalLifecycle, jbossInternalStart, jbossInternalStop, postDeregister, postRegister, preDeregister, preRegister, start, startService, stop, stopService

Methods inherited from class org.jboss.mx.util.JBossNotificationBroadcasterSupport

addNotificationListener, getNotificationInfo, handleNotification, nextNotificationSequenceNumber, removeNotificationListener, removeNotificationListener, sendNotification

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.system.ListenerServiceMBean

setSubscriptionList

Methods inherited from interface org.jboss.system.ServiceMBean

getName, getState, getStateString, jbossInternalLifecycle

Methods inherited from interface org.jboss.system.Service

create, destroy, start, stop

Field Detail

barrier

protected BarrierController.Barrier barrier

The controlled Barrier

Constructor Detail

BarrierController

public BarrierController()

Default CTOR

Method Detail

getBarrierStateString

public String getBarrierStateString()

The controlled barrier StateString.

Specified by:

getBarrierStateString in interface BarrierControllerMBean

setBarrierObjectName

public void setBarrierObjectName(javax.management.ObjectName barrierName)

The controlled barrier ObjectName.

Specified by:

setBarrierObjectName in interface BarrierControllerMBean

getBarrierObjectName

public javax.management.ObjectName getBarrierObjectName()

The controlled barrier ObjectName.

Specified by:

getBarrierObjectName in interface BarrierControllerMBean

setBarrierEnabledOnStartup

public void setBarrierEnabledOnStartup(Boolean enableOnStartup)

The initial state of the barrier. If set, it overrides the internal call to enableOnStartup() which will never get called.

Specified by:

setBarrierEnabledOnStartup in interface BarrierControllerMBean

getBarrierEnabledOnStartup

public Boolean getBarrierEnabledOnStartup()

The initial state of the barrier. Use the value set through setBarrierEnabledOnStartup() otherwise call the internal enableOnStartup() override to make a decision.

Specified by:

getBarrierEnabledOnStartup in interface BarrierControllerMBean

setStartBarrierHandback

public void setStartBarrierHandback(String startHandback)

The notification subscription handback string that starts the barrier.

Specified by:

setStartBarrierHandback in interface BarrierControllerMBean

getStartBarrierHandback

public String getStartBarrierHandback()

The notification subscription handback string that starts the barrier.

Specified by:

getStartBarrierHandback in interface BarrierControllerMBean

setStopBarrierHandback

public void setStopBarrierHandback(String stopHandback)

The notification subscription handback string that stops the barrier.

Specified by:

setStopBarrierHandback in interface BarrierControllerMBean

getStopBarrierHandback

public String getStopBarrierHandback()

The notification subscription handback string that stops the barrier.

Specified by:

getStopBarrierHandback in interface BarrierControllerMBean

setDynamicSubscriptions

public void setDynamicSubscriptions(Boolean dynamicSubscriptions)

The ability to dynamically subscribe for notifications.

Specified by:

setDynamicSubscriptions in interface BarrierControllerMBean

getDynamicSubscriptions

public Boolean getDynamicSubscriptions()

The ability to dynamically subscribe for notifications.

Specified by:

getDynamicSubscriptions in interface BarrierControllerMBean

enableOnStartup

protected Boolean enableOnStartup()

Override this method to apply complex logic whether to start the Barrier service upon startup or not. This method will be only called once and only if setBarrierEnabledOnStartup(Boolean) has not been called. The default implementation is to return false.

createService

protected void createService()
                      throws Exception

Description copied from class: ServiceMBeanSupport

Sub-classes should override this method to provide custum 'create' logic.

This method is empty, and is provided for convenience when concrete service classes do not need to perform anything specific for this state change.

Overrides:

createService in class ServiceMBeanSupport

Throws:

Exception

destroyService

protected void destroyService()

Description copied from class: ServiceMBeanSupport

Sub-classes should override this method to provide custum 'destroy' logic.

This method is empty, and is provided for convenience when concrete service classes do not need to perform anything specific for this state change.

Overrides:

destroyService in class ServiceMBeanSupport

handleNotification2

public void handleNotification2(javax.management.Notification n,
                                Object handback)

Base on the handback object the decision for starting/stopping the barrier

Overrides:

handleNotification2 in class ListenerServiceMBeanSupport

startBarrier

public void startBarrier()

Manually start the controlled barrier

Specified by:

startBarrier in interface BarrierControllerMBean

stopBarrier

public void stopBarrier()

Manually stop the controlled barrier

Specified by:

stopBarrier in interface BarrierControllerMBean