- java.lang.Object
-
- com.sun.management.VMOption
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public class VMOption extends Object
Information about a VM option including its value and where the value came from which is referred as itsorigin
.Each VM option has a default value. A VM option can be set at VM creation time typically as a command line argument to the launcher or an argument passed to the VM created using the JNI invocation interface. In addition, a VM option may be set via an environment variable or a configuration file. A VM option can also be set dynamically via a management interface after the VM was started. A
VMOption
contains the value of a VM option and the origin of that value at the time thisVMOption
object was constructed. The value of the VM option may be changed after theVMOption
object was constructed,- Since:
- 1.6
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
VMOption.Origin
Origin of the value of a VM option.
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Constructor Summary
Constructors Constructor Description VMOption(String name, String value, boolean writeable, VMOption.Origin origin)
Constructs aVMOption
.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description static VMOption
from(CompositeData cd)
Returns aVMOption
object represented by the givenCompositeData
.String
getName()
Returns the name of this VM option.VMOption.Origin
getOrigin()
Returns the origin of the value of this VM option.String
getValue()
Returns the value of this VM option at the time when thisVMOption
was created.boolean
isWriteable()
Tests if this VM option is writeable.
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Constructor Detail
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VMOption
public VMOption(String name, String value, boolean writeable, VMOption.Origin origin)
Constructs aVMOption
.- Parameters:
name
- Name of a VM option.value
- Value of a VM option.writeable
-true
if a VM option can be set dynamically, orfalse
otherwise.origin
- where the value of a VM option came from.- Throws:
NullPointerException
- if the name or value isnull
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Method Detail
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getName
public String getName()
Returns the name of this VM option.- Returns:
- the name of this VM option.
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getValue
public String getValue()
Returns the value of this VM option at the time when thisVMOption
was created. The value could have been changed.- Returns:
- the value of the VM option at the time when
this
VMOption
was created.
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getOrigin
public VMOption.Origin getOrigin()
Returns the origin of the value of this VM option. That is, where the value of this VM option came from.- Returns:
- where the value of this VM option came from.
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isWriteable
public boolean isWriteable()
Tests if this VM option is writeable. If this VM option is writeable, it can be set by theHotSpotDiagnosticMXBean.setVMOption
method.- Returns:
true
if this VM option is writeable;false
otherwise.
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from
public static VMOption from(CompositeData cd)
Returns aVMOption
object represented by the givenCompositeData
. The givenCompositeData
must contain the following attributes:Attribute Name Type name java.lang.String
value java.lang.String
origin java.lang.String
writeable java.lang.Boolean
- Parameters:
cd
-CompositeData
representing aVMOption
- Returns:
- a
VMOption
object represented bycd
ifcd
is notnull
;null
otherwise. - Throws:
IllegalArgumentException
- ifcd
does not represent aVMOption
with the attributes described above.
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