Class GcInfo
- All Implemented Interfaces:
-
CompositeData,CompositeDataView
public class GcInfo extends Object implements CompositeData, CompositeDataView
- Start time
- End time
- Duration
- Memory usage before the collection starts
- Memory usage after the collection ends
GcInfo is a CompositeData The GC-specific attributes can be obtained via the CompositeData interface. This is a historical relic, and other classes should not copy this pattern. Use CompositeDataView instead.
MXBean Mapping
GcInfo is mapped to a CompositeData with attributes as specified in the from method.- Since:
- 1.5
Method Summary
| Modifier and Type | Method | Description |
|---|---|---|
boolean |
containsKey |
Returns true if and only if this CompositeData instance contains an item whose name is key. |
boolean |
containsValue |
Returns true if and only if this CompositeData instance contains an item whose value is value. |
boolean |
equals |
Indicates whether some other object is "equal to" this one. |
static GcInfo |
from |
Returns a GcInfo object represented by the given CompositeData. |
Object |
get |
Returns the value of the item whose name is key. |
Object[] |
getAll |
Returns an array of the values of the items whose names are specified by keys, in the same order as keys. |
CompositeType |
getCompositeType() |
Returns the composite type of this composite data instance. |
long |
getDuration() |
Returns the elapsed time of this GC in milliseconds. |
long |
getEndTime() |
Returns the end time of this GC in milliseconds since the Java virtual machine was started. |
long |
getId() |
Returns the identifier of this garbage collection which is the number of collections that this collector has done. |
Map<String, |
getMemoryUsageAfterGc() |
Returns the memory usage of all memory pools at the end of this GC. |
Map<String, |
getMemoryUsageBeforeGc() |
Returns the memory usage of all memory pools at the beginning of this GC. |
long |
getStartTime() |
Returns the start time of this GC in milliseconds since the Java virtual machine was started. |
int |
hashCode() |
Returns a hash code value for the object. |
CompositeData |
toCompositeData |
Return the CompositeData representation of this GcInfo, including any GC-specific attributes. |
String |
toString() |
Returns a string representation of the object. |
Collection<?> |
values() |
Returns an unmodifiable Collection view of the item values contained in this CompositeData instance. |
Method Details
getId
public long getId()
- Returns:
- the identifier of this garbage collection which is the number of collections that this collector has done.
getStartTime
public long getStartTime()
- Returns:
- the start time of this GC.
getEndTime
public long getEndTime()
- Returns:
- the end time of this GC.
getDuration
public long getDuration()
- Returns:
- the elapsed time of this GC in milliseconds.
getMemoryUsageBeforeGc
public Map<String,MemoryUsage> getMemoryUsageBeforeGc()
Map of the name of a memory pool to the memory usage of the corresponding memory pool before GC starts.- Returns:
- a
Mapof memory pool names to the memory usage of a memory pool before GC starts.
getMemoryUsageAfterGc
public Map<String,MemoryUsage> getMemoryUsageAfterGc()
Map of the name of a memory pool to the memory usage of the corresponding memory pool when GC finishes.- Returns:
- a
Mapof memory pool names to the memory usage of a memory pool when GC finishes.
from
public static GcInfo from(CompositeData cd)
GcInfo object represented by the given CompositeData. The given CompositeData must contain all the following attributes:
Attribute Name Type index java.lang.LongstartTime java.lang.LongendTime java.lang.LongmemoryUsageBeforeGc javax.management.openmbean.TabularDatamemoryUsageAfterGc javax.management.openmbean.TabularData
- Returns:
- a
GcInfoobject represented bycdifcdis notnull;nullotherwise. - Throws:
-
IllegalArgumentException- ifcddoes not represent aGcInfoobject with the attributes described above.
containsKey
public boolean containsKey(String key)
CompositeDatatrue if and only if this CompositeData instance contains an item whose name is key. If key is a null or empty String, this method simply returns false.- Specified by:
-
containsKeyin interfaceCompositeData - Parameters:
-
key- the key to be tested. - Returns:
- true if this
CompositeDatacontains the key.
containsValue
public boolean containsValue(Object value)
CompositeDatatrue if and only if this CompositeData instance contains an item whose value is value.- Specified by:
-
containsValuein interfaceCompositeData - Parameters:
-
value- the value to be tested. - Returns:
- true if this
CompositeDatacontains the value.
equals
public boolean equals(Object obj)
Object The equals method implements an equivalence relation on non-null object references:
- It is reflexive: for any non-null reference value
x,x.equals(x)should returntrue. - It is symmetric: for any non-null reference values
xandy,x.equals(y)should returntrueif and only ify.equals(x)returnstrue. - It is transitive: for any non-null reference values
x,y, andz, ifx.equals(y)returnstrueandy.equals(z)returnstrue, thenx.equals(z)should returntrue. - It is consistent: for any non-null reference values
xandy, multiple invocations ofx.equals(y)consistently returntrueor consistently returnfalse, provided no information used inequalscomparisons on the objects is modified. - For any non-null reference value
x,x.equals(null)should returnfalse.
An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.
- Specified by:
-
equalsin interfaceCompositeData - Overrides:
-
equalsin classObject - Parameters:
-
obj- the reference object with which to compare. - Returns:
-
trueif this object is the same as the obj argument;falseotherwise. - See Also:
get
public Object get(String key)
CompositeDatakey.- Specified by:
-
getin interfaceCompositeData - Parameters:
-
key- the name of the item. - Returns:
- the value associated with this key.
getAll
public Object[] getAll(String[] keys)
CompositeDatakeys, in the same order as keys.- Specified by:
-
getAllin interfaceCompositeData - Parameters:
-
keys- the names of the items. - Returns:
- the values corresponding to the keys.
getCompositeType
public CompositeType getCompositeType()
CompositeData- Specified by:
-
getCompositeTypein interfaceCompositeData - Returns:
- the type of this CompositeData.
hashCode
public int hashCode()
ObjectHashMap. The general contract of hashCode is:
- Whenever it is invoked on the same object more than once during an execution of a Java application, the
hashCodemethod must consistently return the same integer, provided no information used inequalscomparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. - If two objects are equal according to the
equalsmethod, then calling thehashCodemethod on each of the two objects must produce the same integer result. - It is not required that if two objects are unequal according to the
equalsmethod, then calling thehashCodemethod on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
- Specified by:
-
hashCodein interfaceCompositeData - Overrides:
-
hashCodein classObject - Returns:
- a hash code value for this object.
- See Also:
toString
public String toString()
Object- Specified by:
-
toStringin interfaceCompositeData - Overrides:
-
toStringin classObject - Returns:
- a string representation of the object.
values
public Collection<?> values()
CompositeDataCompositeData instance. The returned collection's iterator will return the values in the ascending lexicographic order of the corresponding item names.- Specified by:
-
valuesin interfaceCompositeData - Returns:
- the values.
toCompositeData
public CompositeData toCompositeData(CompositeType ct)
CompositeData representation of this GcInfo, including any GC-specific attributes. The returned value will have at least all the attributes described in the from method, plus optionally other attributes.- Specified by:
-
toCompositeDatain interfaceCompositeDataView - Parameters:
-
ct- theCompositeTypethat the caller expects. This parameter is ignored and can be null. - Returns:
- the
CompositeDatarepresentation.
© 1993, 2021, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/17/docs/api/jdk.management/com/sun/management/GcInfo.html