public class

VMOption

extends Object
java.lang.Object
   ↳ com.sun.management.VMOption

Class Overview

Information about a VM option including its value and where the value came from which is referred as its origin.

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 this VMOption object was constructed. The value of the VM option may be changed after the VMOption object was constructed,

See Also

Summary

Nested Classes
enum VMOption.Origin Origin of the value of a VM option. 
Public Constructors
VMOption(String name, String value, boolean writeable, VMOption.Origin origin)
Constructs a VMOption.
Public Methods
static VMOption from(CompositeData cd)
Returns a VMOption object represented by the given CompositeData.
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 this VMOption was created.
boolean isWriteable()
Tests if this VM option is writeable.
String toString()
Returns a string representation of the object.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public VMOption (String name, String value, boolean writeable, VMOption.Origin origin)

Constructs a VMOption.

Parameters
name Name of a VM option.
value Value of a VM option.
writeable true if a VM option can be set dynamically, or false otherwise.
origin where the value of a VM option came from.
Throws
NullPointerException if the name or value is null

Public Methods

public static VMOption from (CompositeData cd)

Returns a VMOption object represented by the given CompositeData. The given CompositeData 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 a VMOption
Returns
  • a VMOption object represented by cd if cd is not null; null otherwise.
Throws
IllegalArgumentException if cd does not represent a VMOption with the attributes described above.

public String getName ()

Returns the name of this VM option.

Returns
  • the name of this VM option.

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.

public String getValue ()

Returns the value of this VM option at the time when this VMOption was created. The value could have been changed.

Returns
  • the value of the VM option at the time when this VMOption was created.

public boolean isWriteable ()

Tests if this VM option is writeable. If this VM option is writeable, it can be set by the HotSpotDiagnosticMXBean.setVMOption method.

Returns
  • true if this VM option is writeable; false otherwise.

public String toString ()

Returns a string representation of the object. In general, the 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())

Returns
  • a string representation of the object.