@Exported 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 and Description |
---|---|
boolean |
containsKey(String key)
Returns
true if and only if this CompositeData instance contains
an item whose name is key . |
boolean |
containsValue(Object value)
Returns
true if and only if this CompositeData instance contains an item
whose value is value . |
boolean |
equals(Object obj)
Indicates whether some other object is "equal to" this one.
|
static GcInfo |
from(CompositeData cd)
Returns a
GcInfo object represented by the
given CompositeData . |
Object |
get(String key)
Returns the value of the item whose name is
key . |
Object[] |
getAll(String[] keys)
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,MemoryUsage> |
getMemoryUsageAfterGc()
Returns the memory usage of all memory pools
at the end of this GC.
|
Map<String,MemoryUsage> |
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(CompositeType ct)
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)
javax.management.openmbean.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)
javax.management.openmbean.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)
java.lang.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
.
The equals
method for class Object
implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x
and
y
, this method returns true
if and only
if x
and y
refer to the same object
(x == y
has the value true
).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode
method, which states
that equal objects must have equal hash codes.
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.Object.hashCode()
,
HashMap
public Object get(String key)
javax.management.openmbean.CompositeData
key
.get
in interface CompositeData
key
- the name of the item.public Object[] getAll(String[] keys)
javax.management.openmbean.CompositeData
keys
, in the same order as keys
.getAll
in interface CompositeData
keys
- the names of the items.public CompositeType getCompositeType()
javax.management.openmbean.CompositeData
getCompositeType
in interface CompositeData
public int hashCode()
java.lang.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(Object)
method, then calling the hashCode
method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
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.
As much as is reasonably practical, the hashCode method defined
by class Object
does return distinct integers for
distinct objects. (The hashCode may or may not be implemented
as some function of an object's memory address at some point
in time.)
hashCode
in interface CompositeData
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public String toString()
java.lang.Object
toString
method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString
method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@
', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
toString
in interface CompositeData
toString
in class Object
public Collection<?> values()
javax.management.openmbean.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.
Copyright © 2003, 2015, Oracle and/or its affiliates. All rights reserved.
DRAFT internal-b94