Class GarbageCollectionNotificationInfo
- All Implemented Interfaces:
CompositeDataView
public class GarbageCollectionNotificationInfo extends Object implements CompositeDataView
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
GcInfoobject 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
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 |
Constructs a GarbageCollectionNotificationInfo object. |
Method Summary
| Modifier and Type | Method | Description |
|---|---|---|
static GarbageCollectionNotificationInfo |
from |
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 |
Return a CompositeData corresponding to the values in this object. |
Field Details
GARBAGE_COLLECTION_NOTIFICATION
public static final String GARBAGE_COLLECTION_NOTIFICATION
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)
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
getGcAction
public String getGcAction()
- Returns:
- the action performed by the garbage collector
getGcCause
public String getGcCause()
- Returns:
- the cause of the garbage collection
getGcInfo
public GcInfo getGcInfo()
- Returns:
- the GC information related to the last garbage collection
from
public static GarbageCollectionNotificationInfo from(CompositeData cd)
GarbageCollectionNotificationInfo object represented by the given CompositeData. The given CompositeData must contain the following attributes:
Attribute Name Type gcName java.lang.StringgcAction java.lang.StringgcCause java.lang.StringgcInfo javax.management.openmbean.CompositeData
- Parameters:
-
cd-CompositeDatarepresenting aGarbageCollectionNotificationInfo - Returns:
- a
GarbageCollectionNotificationInfoobject represented bycdifcdis notnull;nullotherwise. - Throws:
-
IllegalArgumentException- ifcddoes not represent aGarbaageCollectionNotificationInfoobject.
toCompositeData
public CompositeData toCompositeData(CompositeType ct)
CompositeDataViewReturn 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:
-
toCompositeDatain interfaceCompositeDataView - Parameters:
-
ct- The expectedCompositeTypeof the returned value. If the returned value iscd, thencd.getCompositeType().equals(ct)should be true. Typically this will be becausecdis aCompositeDataSupportconstructed withctas itsCompositeType. - Returns:
- the
CompositeData.
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/17/docs/api/jdk.management/com/sun/management/GarbageCollectionNotificationInfo.html