Package wt.jmx.core

Class SelfAwareMBean

java.lang.Object
javax.management.StandardMBean
wt.jmx.core.StandardMBean
wt.jmx.core.SelfAwareMBean
All Implemented Interfaces:
DynamicMBean, MBeanRegistration, BaseObjectNamed
Direct Known Subclasses:
wt.jmx.core.mbeans.AbstractFileView, AbstractPlugin, CompositeQueueDataBean, wt.jmx.core.mbeans.DeluxeStatsMonitor, Dumper, Emailer, FilteredMCLogger, FilteredRequestLogger, FocusedUserFilter, GarbageCollectionMonitor, HeapDumpDelegate, Info, IPRequestTracker, JavaProcessMonitor, MainCacheManager, MBeanLoader, MCHistogrammer, NotificationScriptAction, PeriodicMemoryDumperDelegate, RequestHistogrammer, ServerManagerMonitor, SummaryScriptAction
public abstract class SelfAwareMBean extends StandardMBean implements MBeanRegistration, BaseObjectNamed
StandardMBean subclass that knows its own ObjectName -- and thus assumes it is only registered once. Instances of this class can optionally be told of another MBean that plays an "owner" role and derive their ObjectName from this other MBean's ObjectName. This class also provides init(), start(), stop(), and destroy() lifecycle methods for purposes of [de]registering dependent MBeans, starting/stopping background tasks, etc.

Supported API: true

Extendable: true

  • Constructor Details

    • SelfAwareMBean

      public SelfAwareMBean(T implementation, Class<T> mbeanInterface) throws NotCompliantMBeanException
      Pass through constructor

      Supported API: true
      Throws:
      NotCompliantMBeanException

    • SelfAwareMBean

      public SelfAwareMBean(T implementation, Class<T> mbeanInterface, boolean isMXBean)
      Pass through constructor

      Supported API: true

    • SelfAwareMBean

      protected SelfAwareMBean(Class<?> mbeanInterface) throws NotCompliantMBeanException
      Pass through constructor

      Supported API: true
      Throws:
      NotCompliantMBeanException

    • SelfAwareMBean

      protected SelfAwareMBean(Class<?> mbeanInterface, boolean isMXBean)
      Pass through constructor

      Supported API: true

  • Method Details

    • isRegistered

      public final boolean isRegistered()
      Returns whether this MBean is currently registered with an MBeanServer

      Supported API: true

    • isInited

      public final boolean isInited()
      Returns whether this MBean is currently inited, i.e. init() has been called but destroy() has not

      Supported API: true

    • isStarted

      public final boolean isStarted()
      Returns whether this MBean is currently started, i.e. start() has been called more recently than stop()

      Supported API: true

    • getObjectName

      public final ObjectName getObjectName()
      Returns the ObjectName of this MBean

      Supported API: true

    • getBaseObjectName

      public ObjectName getBaseObjectName()
      Required method for BaseObjectNamed interface. Returns the ObjectName of this MBean in this class, but allows subclasses to direct children to a separate ObjectName base than themselves by overriding this method.

      Supported API: true
      Specified by:
      getBaseObjectName in interface BaseObjectNamed

    • getOwnerMBean

      public BaseObjectNamed getOwnerMBean()
      Returns the MBean that acts as a parent or owner to this MBean

      Supported API: true

    • setOwnerMBean

      public void setOwnerMBean(BaseObjectNamed ownerMBean)
      Sets the MBean that acts as a parent or owner to this MBean

      Supported API: true

    • deregister

      public void deregister()
      Deregister the given MBean.

      Note: Such MBeans are not necessarily cognizant of MBeans that aggregate them, so calls to deregister() other than by such aggregating MBeans themselves or on non-aggregated MBeans should be avoided. Aggregated MBeans really seem to be a use case for the JMX relationship service -- except that the relationship service is extraordinarily complex and unwieldy.

      Supported API: true

    • register

      public ObjectName register()
      Register MBean with MBeanServer.

      ObjectName used is determined by preRegister().

      Supported API: true

    • register

      public ObjectName register(ObjectName baseObjectName)
      Register MBean with MBeanServer.

      If 'baseObjectName' is non-null, it is used to produce an appropriate ObjectName for this MBean from this and the result of getObjectNameSuffix(), otherwise the object name is produced by preRegister() as in register().

      Supported API: true

    • register

      public ObjectName register(BaseObjectNamed parentMBean)
      The BaseObjectNamed argument is used to set the OwnerMBean attribute, clears the MBean's ObjectName, and then registers this MBean if and only if 'parentMBean' is either not a SelfAwareMBean or is currently registered. The ObjectName of the MBean will be derived by preRegister().

      If 'parentMBean' is a SelfAwareMBean then it is assumed its registration status will not change during the duration of this call. Callers should synchronize against 'parentMBean' if necessary to enforce this assumption. [Such synchronization is not done within this routine so as not to produce issues of lock ordering, e.g. deadlocks.]

      Supported API: true

    • resetObjectName

      public void resetObjectName()
      If not registered, but had been registered, this will reset the ObjectName within this instance thus allowing it to be re-registered under another name.

      Supported API: true

    • init

      public final void init()
      Lifecycle method which marks this MBean as inited (ala isInited()) and then delegates to onInit(). This method will automatically be called prior to onStart() by the first start() invocation if it has not been called by that point. It may, however, be invoked at any point prior to this as well.

      This method generally embodies one-time post-construction initialization to be cleaned up in destroy(), though one can reintialize a destroy()'ed MBean.

      This method is a no-op if the MBean is already inited.

      Supported API: true

    • destroy

      public final void destroy()
      Lifecycle method which deregisters (and thus stops) the MBean, delegates to onDestroy(), and finally marks this MBean as not inited (ala isInited()).

      This method generally embodies the inverse of init().

      This method is a no-op if the MBean is not inited.

      Supported API: true

    • start

      public final void start()
      Lifecycle method which calls init() if the MBean is not yet inited, marks the MBean as started, and then delegates to onStart(). This method will automatically be called during MBean registration unless isAutoStart() returns false. An IllegalStateException will be thrown if this method is called when the MBean is not registered.

      start() and stop() may be called while an MBean is registered without registering and deregistering the MBean, but such usage is atypical. Rather this method generally embodies an "on registration" notion.

      This method is a no-op if the MBean is already started.

      Supported API: true

    • stop

      public final void stop()
      Lifecycle method which delegates to onStop() and then marks the MBean as not started. This method will automatically be called during MBean deregistration.

      stop() may be called while an MBean is registered without deregistering the MBean, but such usage is atypical. Rather this method generally embodies an "on deregistration" notion.

      This method is a no-op if the MBean is not started.

      Supported API: true

    • onInit

      protected void onInit()
      Intended for override by sub-classes that need to do initialization during init(), which calls it.

      Generally this is used for any initialization that must be done after construction, but not done and undone by start() and stop(). onInit() and onDestroy() should generally be near inverse operations of one another.

      Overrides of this method should call super.onInit() and do so before their own intialization code in order to obtain proper execution of super-classes' onInit()'s as well.

      Supported API: true

    • onDestroy

      protected void onDestroy()
      Intended for override by sub-classes that need to do cleanup during destroy(), which calls it.

      Generally this is used for any cleanup that is necessary after stop() that will not be handled in an efficient and timely manner by garbage collection. onInit() and onDestroy() should generally be near inverse operations of one another.

      Overrides of this method should call super.onDestroy() and do so after their own cleanup code in order to obtain proper execution of super-classes' onDestroy()'s as well.

      Supported API: true

    • onStart

      protected void onStart()
      Intended for override by sub-classes that need to do initialization during start(), which calls it.

      Generally this is used for any initialization should be delayed until the MBean is registered and that should be undone as part of unregistering the MBean. onStart() and onStop() should generally be near inverse operations of one another.

      Overrides of this method should call super.onStart() and do so before their own intialization code in order to obtain proper execution of super-classes' onStart()'s as well.

      Supported API: true

    • onStop

      protected void onStop()
      Intended for override by sub-classes that need to do cleanup during stop(), which calls it.

      Generally this is used for any cleanup that should be done prior to or coincident with unregistering the MBean. onStart() and onStop() should generally be nearly inverse operations of one another.

      Overrides of this method should call super.onStop() and do so after their own cleanup code in order to obtain proper execution of super-classes' onStop()'s as well.

      Supported API: true

    • getObjectNameSuffix

      public abstract String[][] getObjectNameSuffix()
      Provide a set of name/value pairs for use as a suffix in creating a new ObjectName for an MBean instance based on an existing ObjectName used as a context / namespace prefix.

      Supported API: true

    • preRegister

      public ObjectName preRegister(MBeanServer server, ObjectName name) throws Exception
      Required method for MBeanRegistration interface. If caller provided ObjectName is null will use the existing ObjectName of this MBean if it is already known (e.g. from a previous registration) if it is non-null. If this too is null, will use the ObjectName provided by getObjectNameOnPreRegister().

      Supported API: true
      Specified by:
      preRegister in interface MBeanRegistration
      Overrides:
      preRegister in class StandardMBean
      Throws:
      Exception

    • getObjectNameOnPreRegister

      protected ObjectName getObjectNameOnPreRegister() throws Exception
      Called from within preRegister() if ObjectName passed in is null and this object does not yet have its own object name.

      This implementation computes an ObjectName by using the owner MBean's base object name as a prefix and getObjectNameSuffix() as a suffix when this bean has an owner MBean and the owner has a non-null base object name. Otherwise it uses MBeanRegistry.DOMAIN_NAME and getObjectNameSuffix().

      Supported API: true

      Throws:
      Exception

    • postRegister

      public void postRegister(Boolean registrationDone)
      Required method for MBeanRegistration interface. Calls start() if MBean is not already started. Registers MBean for access via getSelfAwareMBean().

      Supported API: true
      Specified by:
      postRegister in interface MBeanRegistration
      Overrides:
      postRegister in class StandardMBean

    • preDeregister

      public void preDeregister() throws Exception
      Required method for MBeanRegistration interface. De-registers MBean for access via getSelfAwareMBean().

      Supported API: true
      Specified by:
      preDeregister in interface MBeanRegistration
      Overrides:
      preDeregister in class StandardMBean
      Throws:
      Exception

    • postDeregister

      public void postDeregister()
      Required method for MBeanRegistration interface. Calls stop() if MBean is started.

      Supported API: true
      Specified by:
      postDeregister in interface MBeanRegistration
      Overrides:
      postDeregister in class StandardMBean

    • getSelfAwareMBean

      public static SelfAwareMBean getSelfAwareMBean(ObjectName objectName)
      Get SelfAwareMBean with the given 'objectName' if such an MBean is currently registered.

      Supported API: true