java.lang.Object
com.sun.management.GcInfo
- All Implemented Interfaces:
CompositeData
,CompositeDataView
Garbage collection information. It contains the following
information for one garbage collection as well as GC-specific
attributes:
- 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 TypeMethodDescriptionboolean
containsKey
(String key) Returnstrue
if and only if thisCompositeData
instance contains an item whose name iskey
.boolean
containsValue
(Object value) Returnstrue
if and only if thisCompositeData
instance contains an item whose value isvalue
.boolean
Indicates whether some other object is "equal to" this one.static GcInfo
from
(CompositeData cd) Returns aGcInfo
object represented by the givenCompositeData
.Returns the value of the item whose name iskey
.Object[]
Returns an array of the values of the items whose names are specified bykeys
, in the same order askeys
.Returns the composite type of this composite data instance.long
Returns the elapsed time of this GC in milliseconds.long
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.Returns the memory usage of all memory pools at the end of this GC.Returns the memory usage of all memory pools at the beginning of this GC.long
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.Return theCompositeData
representation of thisGcInfo
, including any GC-specific attributes.toString()
Returns a string representation of the object.Collection
<?> values()
Returns an unmodifiable Collection view of the item values contained in thisCompositeData
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.- 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 in milliseconds since the Java virtual machine was started.- Returns:
- the start time of this GC.
-
getEndTime
public long getEndTime()Returns the end time of this GC in milliseconds since the Java virtual machine was started.- Returns:
- the end time of this GC.
-
getDuration
public long getDuration()Returns the elapsed time of this GC in milliseconds.- Returns:
- the elapsed time of this GC in milliseconds.
-
getMemoryUsageBeforeGc
Returns the memory usage of all memory pools at the beginning of this GC. This method returns aMap
of the name of a memory pool to the memory usage of the corresponding memory pool before GC starts.- Returns:
- a
Map
of memory pool names to the memory usage of a memory pool before GC starts.
-
getMemoryUsageAfterGc
Returns the memory usage of all memory pools at the end of this GC. This method returns aMap
of the name of a memory pool to the memory usage of the corresponding memory pool when GC finishes.- Returns:
- a
Map
of memory pool names to the memory usage of a memory pool when GC finishes.
-
from
Returns aGcInfo
object represented by the givenCompositeData
. The givenCompositeData
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
- Returns:
- a
GcInfo
object represented bycd
ifcd
is notnull
;null
otherwise. - Throws:
IllegalArgumentException
- ifcd
does not represent aGcInfo
object with the attributes described above.
-
containsKey
Description copied from interface:CompositeData
Returnstrue
if and only if thisCompositeData
instance contains an item whose name iskey
. Ifkey
is a null or empty String, this method simply returns false.- Specified by:
containsKey
in interfaceCompositeData
- Parameters:
key
- the key to be tested.- Returns:
- true if this
CompositeData
contains the key.
-
containsValue
Description copied from interface:CompositeData
Returnstrue
if and only if thisCompositeData
instance contains an item whose value isvalue
.- Specified by:
containsValue
in interfaceCompositeData
- Parameters:
value
- the value to be tested.- Returns:
- true if this
CompositeData
contains the value.
-
equals
Description copied from class:Object
Indicates whether some other object is "equal to" this one.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
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons 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:
equals
in interfaceCompositeData
- Overrides:
equals
in classObject
- Parameters:
obj
- the reference object with which to compare.- Returns:
true
if this object is the same as the obj argument;false
otherwise.- See Also:
- It is reflexive: for any non-null reference value
-
get
Description copied from interface:CompositeData
Returns the value of the item whose name iskey
.- Specified by:
get
in interfaceCompositeData
- Parameters:
key
- the name of the item.- Returns:
- the value associated with this key.
-
getAll
Description copied from interface:CompositeData
Returns an array of the values of the items whose names are specified bykeys
, in the same order askeys
.- Specified by:
getAll
in interfaceCompositeData
- Parameters:
keys
- the names of the items.- Returns:
- the values corresponding to the keys.
-
getCompositeType
Description copied from interface:CompositeData
Returns the composite type of this composite data instance.- Specified by:
getCompositeType
in interfaceCompositeData
- Returns:
- the type of this CompositeData.
-
hashCode
public int hashCode()Description copied from class:Object
Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided byHashMap
.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
hashCode
method must consistently return the same integer, provided no information used inequals
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. - If two objects are equal according to the
equals
method, then calling thehashCode
method 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
equals
method, then calling thehashCode
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.
- Specified by:
hashCode
in interfaceCompositeData
- Overrides:
hashCode
in classObject
- Returns:
- a hash code value for this object.
- See Also:
- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
-
toString
Description copied from class:Object
Returns a string representation of the object.- Specified by:
toString
in interfaceCompositeData
- Overrides:
toString
in classObject
- Returns:
- a string representation of the object.
-
values
Description copied from interface:CompositeData
Returns an unmodifiable Collection view of the item values contained in thisCompositeData
instance. The returned collection's iterator will return the values in the ascending lexicographic order of the corresponding item names.- Specified by:
values
in interfaceCompositeData
- Returns:
- the values.
-
toCompositeData
Return theCompositeData
representation of thisGcInfo
, including any GC-specific attributes. The returned value will have at least all the attributes described in thefrom
method, plus optionally other attributes.- Specified by:
toCompositeData
in interfaceCompositeDataView
- Parameters:
ct
- theCompositeType
that the caller expects. This parameter is ignored and can be null.- Returns:
- the
CompositeData
representation.
-