Monitoring and Management Interface for the Java Platform

com.sun.management
Class VMOption

java.lang.Object
  extended by com.sun.management.VMOption

public class VMOption
extends Object

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,

Since:
1.6
See Also:
Java Virtual Machine

Nested Class Summary
static class VMOption.Origin
          Origin of the value of a VM option.
 
Constructor Summary
VMOption(String name, String value, boolean writeable, VMOption.Origin origin)
          Constructs a VMOption.
 
Method Summary
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()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

VMOption

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
Method Detail

getName

public String getName()
Returns the name of this VM option.

Returns:
the name of this VM option.

getValue

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.

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.

isWriteable

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.

toString

public String toString()
Overrides:
toString in class Object

from

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.

Monitoring and Management Interface for the Java Platform

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