java.lang.Object
javax.management.NotificationBroadcasterSupport
javax.management.monitor.Monitor
- All Implemented Interfaces:
MBeanRegistration,MonitorMBean,NotificationBroadcaster,NotificationEmitter
- Direct Known Subclasses:
CounterMonitor,GaugeMonitor,StringMonitor
public abstract class Monitor
extends NotificationBroadcasterSupport
implements MonitorMBean, MBeanRegistration
Defines the part common to all monitor MBeans.
A monitor MBean monitors values of an attribute common to a set of observed
MBeans. The observed attribute is monitored at intervals specified by the
granularity period. A gauge value (derived gauge) is derived from the values
of the observed attribute.
- Since:
- 1.5
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected intDeprecated.protected int[]Selected monitor errors that have already been notified.protected static final intThe amount by which the capacity of the monitor arrays are automatically incremented when their size becomes greater than their capacity.protected StringDeprecated.No replacement.protected intThe number of valid components in the vector of observed objects.protected static final intFlag denoting that a notification has occurred after changing the observed attribute.protected static final intFlag denoting that a notification has occurred after changing the observed object or the observed attribute.protected static final intFlag denoting that a notification has occurred after changing the observed object.protected static final intThis flag is used to reset thealreadyNotifiedsmonitor attribute.protected static final intFlag denoting that a notification has occurred after changing the observed object or the observed attribute.protected MBeanServerReference to the MBean server. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoidaddObservedObject(ObjectName object) Adds the specified object in the set of observed MBeans, if this object is not already present.booleancontainsObservedObject(ObjectName object) Tests whether the specified object is in the set of observed MBeans.longGets the granularity period (in milliseconds).Gets the attribute being observed.Deprecated.As of JMX 1.2, replaced bygetObservedObjects()Returns an array containing the objects being observed.booleanisActive()Tests whether the monitor MBean is active.voidAllows the monitor MBean to perform any operations needed after having been unregistered by the MBean server.voidpostRegister(Boolean registrationDone) Allows the monitor MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.voidAllows the monitor MBean to perform any operations it needs before being unregistered by the MBean server.preRegister(MBeanServer server, ObjectName name) Allows the monitor MBean to perform any operations it needs before being registered in the MBean server.voidremoveObservedObject(ObjectName object) Removes the specified object from the set of observed MBeans.voidsetGranularityPeriod(long period) Sets the granularity period (in milliseconds).voidsetObservedAttribute(String attribute) Sets the attribute to observe.voidsetObservedObject(ObjectName object) Deprecated.As of JMX 1.2, replaced byaddObservedObject(javax.management.ObjectName)abstract voidstart()Starts the monitor.abstract voidstop()Stops the monitor.Methods declared in class javax.management.NotificationBroadcasterSupport
addNotificationListener, getNotificationInfo, handleNotification, removeNotificationListener, removeNotificationListener, sendNotification
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Field Details
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capacityIncrement
protected static final int capacityIncrementThe amount by which the capacity of the monitor arrays are automatically incremented when their size becomes greater than their capacity.- See Also:
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elementCount
protected int elementCountThe number of valid components in the vector of observed objects. -
alreadyNotified
Deprecated.equivalent toalreadyNotifieds[0].Monitor errors that have already been notified. -
alreadyNotifieds
protected int[] alreadyNotifiedsSelected monitor errors that have already been notified.
Each element in this array corresponds to an observed object in the vector. It contains a bit mask of the flags
OBSERVED_OBJECT_ERROR_NOTIFIEDetc, indicating whether the corresponding notification has already been sent for the MBean being monitored. -
server
Reference to the MBean server. This reference is null when the monitor MBean is not registered in an MBean server. This reference is initialized before the monitor MBean is registered in the MBean server.- See Also:
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RESET_FLAGS_ALREADY_NOTIFIED
protected static final int RESET_FLAGS_ALREADY_NOTIFIEDThis flag is used to reset thealreadyNotifiedsmonitor attribute.- See Also:
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OBSERVED_OBJECT_ERROR_NOTIFIED
protected static final int OBSERVED_OBJECT_ERROR_NOTIFIEDFlag denoting that a notification has occurred after changing the observed object. This flag is used to check that the new observed object is registered in the MBean server at the time of the first notification.- See Also:
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OBSERVED_ATTRIBUTE_ERROR_NOTIFIED
protected static final int OBSERVED_ATTRIBUTE_ERROR_NOTIFIEDFlag denoting that a notification has occurred after changing the observed attribute. This flag is used to check that the new observed attribute belongs to the observed object at the time of the first notification.- See Also:
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OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED
protected static final int OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIEDFlag denoting that a notification has occurred after changing the observed object or the observed attribute. This flag is used to check that the observed attribute type is correct (depending on the monitor in use) at the time of the first notification.- See Also:
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RUNTIME_ERROR_NOTIFIED
protected static final int RUNTIME_ERROR_NOTIFIEDFlag denoting that a notification has occurred after changing the observed object or the observed attribute. This flag is used to notify any exception (except the cases described above) when trying to get the value of the observed attribute at the time of the first notification.- See Also:
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dbgTag
Deprecated.No replacement.This field is retained for compatibility but should not be referenced.
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Constructor Details
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Monitor
public Monitor()Constructor for subclasses to call.
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Method Details
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preRegister
Allows the monitor MBean to perform any operations it needs before being registered in the MBean server.Initializes the reference to the MBean server.
- Specified by:
preRegisterin interfaceMBeanRegistration- Parameters:
server- The MBean server in which the monitor MBean will be registered.name- The object name of the monitor MBean.- Returns:
- The name of the monitor MBean registered.
- Throws:
Exception- if something goes wrong
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postRegister
Allows the monitor MBean to perform any operations needed after having been registered in the MBean server or after the registration has failed.Not used in this context.
- Specified by:
postRegisterin interfaceMBeanRegistration- Parameters:
registrationDone- Indicates whether or not the MBean has been successfully registered in the MBean server. The value false means that the registration phase has failed.
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preDeregister
Allows the monitor MBean to perform any operations it needs before being unregistered by the MBean server.Stops the monitor.
- Specified by:
preDeregisterin interfaceMBeanRegistration- Throws:
Exception- if something goes wrong
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postDeregister
public void postDeregister()Allows the monitor MBean to perform any operations needed after having been unregistered by the MBean server.Not used in this context.
- Specified by:
postDeregisterin interfaceMBeanRegistration
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start
public abstract void start()Starts the monitor.- Specified by:
startin interfaceMonitorMBean
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stop
public abstract void stop()Stops the monitor.- Specified by:
stopin interfaceMonitorMBean
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getObservedObject
Deprecated.As of JMX 1.2, replaced bygetObservedObjects()Returns the object name of the first object in the set of observed MBeans, ornullif there is no such object.- Specified by:
getObservedObjectin interfaceMonitorMBean- Returns:
- The object being observed.
- See Also:
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setObservedObject
Deprecated.As of JMX 1.2, replaced byaddObservedObject(javax.management.ObjectName)Removes all objects from the set of observed objects, and then adds the specified object.- Specified by:
setObservedObjectin interfaceMonitorMBean- Parameters:
object- The object to observe.- Throws:
IllegalArgumentException- The specified object is null.- See Also:
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addObservedObject
Adds the specified object in the set of observed MBeans, if this object is not already present.- Specified by:
addObservedObjectin interfaceMonitorMBean- Parameters:
object- The object to observe.- Throws:
IllegalArgumentException- The specified object is null.
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removeObservedObject
Removes the specified object from the set of observed MBeans.- Specified by:
removeObservedObjectin interfaceMonitorMBean- Parameters:
object- The object to remove.
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containsObservedObject
Tests whether the specified object is in the set of observed MBeans.- Specified by:
containsObservedObjectin interfaceMonitorMBean- Parameters:
object- The object to check.- Returns:
trueif the specified object is present,falseotherwise.
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getObservedObjects
Returns an array containing the objects being observed.- Specified by:
getObservedObjectsin interfaceMonitorMBean- Returns:
- The objects being observed.
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getObservedAttribute
Gets the attribute being observed.
The observed attribute is not initialized by default (set to null).- Specified by:
getObservedAttributein interfaceMonitorMBean- Returns:
- The attribute being observed.
- See Also:
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setObservedAttribute
Sets the attribute to observe.
The observed attribute is not initialized by default (set to null).- Specified by:
setObservedAttributein interfaceMonitorMBean- Parameters:
attribute- The attribute to observe.- Throws:
IllegalArgumentException- The specified attribute is null.- See Also:
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getGranularityPeriod
public long getGranularityPeriod()Gets the granularity period (in milliseconds).
The default value of the granularity period is 10 seconds.- Specified by:
getGranularityPeriodin interfaceMonitorMBean- Returns:
- The granularity period value.
- See Also:
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setGranularityPeriod
Sets the granularity period (in milliseconds).
The default value of the granularity period is 10 seconds.- Specified by:
setGranularityPeriodin interfaceMonitorMBean- Parameters:
period- The granularity period value.- Throws:
IllegalArgumentException- The granularity period is less than or equal to zero.- See Also:
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isActive
public boolean isActive()Tests whether the monitor MBean is active. A monitor MBean is marked active when thestartmethod is called. It becomes inactive when thestopmethod is called.- Specified by:
isActivein interfaceMonitorMBean- Returns:
trueif the monitor MBean is active,falseotherwise.
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alreadyNotifieds[0].