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.
GcInfo
is mapped to a CompositeData
with attributes as specified in the from
method.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 |
getMemoryUsageAfterGc() |
Returns the memory usage of all memory pools at the end of this GC. |
Map |
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. |
public long getId()
public long getStartTime()
public long getEndTime()
public long getDuration()
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.Map
of memory pool names to the memory usage of a memory pool before GC starts.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.Map
of memory pool names to the memory usage of a memory pool when GC finishes.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.Long
startTime java.lang.Long
endTime java.lang.Long
memoryUsageBeforeGc javax.management.openmbean.TabularData
memoryUsageAfterGc javax.management.openmbean.TabularData
GcInfo
object represented by cd
if cd
is not null
; null
otherwise.IllegalArgumentException
- if cd
does not represent a GcInfo
object with the attributes described above.public boolean containsKey(String key)
CompositeData
true
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.containsKey
in interface CompositeData
key
- the key to be tested.CompositeData
contains the key.public boolean containsValue(Object value)
CompositeData
true
if and only if this CompositeData
instance contains an item whose value is value
.containsValue
in interface CompositeData
value
- the value to be tested.CompositeData
contains the value.public boolean equals(Object obj)
Object
The equals
method implements an equivalence relation on non-null object references:
x
, x.equals(x)
should return true
. x
and y
, x.equals(y)
should return true
if and only if y.equals(x)
returns true
. x
, y
, and z
, if x.equals(y)
returns true
and y.equals(z)
returns true
, then x.equals(z)
should return true
. x
and y
, multiple invocations of x.equals(y)
consistently return true
or consistently return false
, provided no information used in equals
comparisons on the objects is modified. x
, x.equals(null)
should return false
. 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.
equals
in interface CompositeData
equals
in class Object
obj
- the reference object with which to compare.true
if this object is the same as the obj argument; false
otherwise.public Object get(String key)
CompositeData
key
.get
in interface CompositeData
key
- the name of the item.public Object[] getAll(String[] keys)
CompositeData
keys
, in the same order as keys
.getAll
in interface CompositeData
keys
- the names of the items.public CompositeType getCompositeType()
CompositeData
getCompositeType
in interface CompositeData
public int hashCode()
Object
HashMap
. The general contract of hashCode
is:
hashCode
method must consistently return the same integer, provided no information used in equals
comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. equals
method, then calling the
hashCode
method on each of the two objects must produce the same integer result. equals
method, then calling the hashCode
method 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. hashCode
in interface CompositeData
hashCode
in class Object
public String toString()
Object
toString
in interface CompositeData
toString
in class Object
public Collection<?> values()
CompositeData
CompositeData
instance. The returned collection's iterator will return the values in the ascending lexicographic order of the corresponding item names.values
in interface CompositeData
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.toCompositeData
in interface CompositeDataView
ct
- the CompositeType
that the caller expects. This parameter is ignored and can be null.CompositeData
representation.
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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.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/GcInfo.html