Class GarbageCollectionNotificationInfo

java.lang.Object

com.sun.management.GarbageCollectionNotificationInfo

All Implemented Interfaces:: CompositeDataView

public class GarbageCollectionNotificationInfo extends Object implements CompositeDataView

The information about a garbage collection

A garbage collection notification is emitted by GarbageCollectorMXBean when the Java virtual machine completes a garbage collection action The notification emitted will contain the garbage collection notification information about the status of the memory:

The name of the garbage collector used to perform the collection.
The action performed by the garbage collector.
The cause of the garbage collection action.
A GcInfo object containing some statistics about the GC cycle (start time, end time) and the memory usage before and after the GC cycle.

A CompositeData representing the GarbageCollectionNotificationInfo object is stored in the userdata of a notification. The from method is provided to convert from a CompositeData to a GarbageCollectionNotificationInfo object. For example:

     Notification notif;

     // receive the notification emitted by a GarbageCollectorMXBean and set to notif
     ...

     String notifType = notif.getType();
     if (notifType.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
         // retrieve the garbage collection notification information
         CompositeData cd = (CompositeData) notif.getUserData();
         GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from(cd);
         ....
     }

The type of the notification emitted by a GarbageCollectorMXBean is:

A garbage collection notification.
Used by every notification emitted by the garbage collector, the details about the notification are provided in the action String

Since:: 1.7

Field Summary

Modifier and Type	Field	Description
`static final String`	`GARBAGE_COLLECTION_NOTIFICATION`	Notification type denoting that the Java virtual machine has completed a garbage collection cycle.

Constructor Summary

Constructor	Description
`GarbageCollectionNotificationInfo(String gcName, String gcAction, String gcCause, GcInfo gcInfo)`	Constructs a `GarbageCollectionNotificationInfo` object.

Method Summary

Modifier and Type	Method	Description
`static GarbageCollectionNotificationInfo`	`from(CompositeData cd)`	Returns a `GarbageCollectionNotificationInfo` object represented by the given `CompositeData`.
`String`	`getGcAction()`	Returns the action performed by the garbage collector
`String`	`getGcCause()`	Returns the cause of the garbage collection
`GcInfo`	`getGcInfo()`	Returns the GC information related to the last garbage collection
`String`	`getGcName()`	Returns the name of the garbage collector used to perform the collection
`CompositeData`	`toCompositeData(CompositeType ct)`	Return a `CompositeData` corresponding to the values in this object.

Methods declared in class Object

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

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details

GARBAGE_COLLECTION_NOTIFICATION

public static final String GARBAGE_COLLECTION_NOTIFICATION

Notification type denoting that the Java virtual machine has completed a garbage collection cycle. This notification is emitted by a GarbageCollectorMXBean. The value of this notification type is com.sun.management.gc.notification.

See Also:

Constructor Details

GarbageCollectionNotificationInfo

public GarbageCollectionNotificationInfo(String gcName, String gcAction, String gcCause, GcInfo gcInfo)

Constructs a GarbageCollectionNotificationInfo object.

Parameters:: gcName - The name of the garbage collector used to perform the collection; gcAction - The name of the action performed by the garbage collector; gcCause - The cause of the garbage collection action; gcInfo - a GcInfo object providing statistics about the GC cycle

Method Details

getGcName

public String getGcName()

Returns the name of the garbage collector used to perform the collection

Returns:: the name of the garbage collector used to perform the collection

getGcAction

public String getGcAction()

Returns the action performed by the garbage collector

Returns:: the action performed by the garbage collector

getGcCause

public String getGcCause()

Returns the cause of the garbage collection

Returns:: the cause of the garbage collection

getGcInfo

public GcInfo getGcInfo()

Returns the GC information related to the last garbage collection

Returns:: the GC information related to the last garbage collection

from

public static GarbageCollectionNotificationInfo from(CompositeData cd)

Returns a GarbageCollectionNotificationInfo object represented by the given CompositeData. The given CompositeData must contain the following attributes:

description

Attribute Name Type

gcName java.lang.String

gcAction java.lang.String

gcCause java.lang.String

gcInfo javax.management.openmbean.CompositeData

description
Attribute Name	Type
gcName	`java.lang.String`
gcAction	`java.lang.String`
gcCause	`java.lang.String`
gcInfo	`javax.management.openmbean.CompositeData`

Parameters:: cd - CompositeData representing a GarbageCollectionNotificationInfo
Returns:: a GarbageCollectionNotificationInfo object represented by cd if cd is not null; null otherwise.
Throws:: IllegalArgumentException - if cd does not represent a GarbaageCollectionNotificationInfo object.

toCompositeData

public CompositeData toCompositeData(CompositeType ct)

Description copied from interface: CompositeDataView

Return a CompositeData corresponding to the values in this object. The returned value should usually be an instance of CompositeDataSupport, or a class that serializes as a CompositeDataSupport via a writeReplace method. Otherwise, a remote client that receives the object might not be able to reconstruct it.

Specified by:: toCompositeData in interface CompositeDataView
Parameters:: ct - The expected CompositeType of the returned value. If the returned value is cd, then cd.getCompositeType().equals(ct) should be true. Typically this will be because cd is a CompositeDataSupport constructed with ct as its CompositeType.
Returns:: the CompositeData.

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