Class VMOption

java.lang.Object
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

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    VMOption.Origin
    Origin of the value of a VM option.

  • Constructor Summary

    Constructors
    Constructor
    Description
    VMOption(String name, String value, boolean writeable, VMOption.Origin origin)
    Constructs a VMOption.

  • Method Summary

    Modifier and Type
    Method
    Description
    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.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Creates and returns a copy of this object.
    boolean
    equals(Object obj)
    Indicates whether some other object is "equal to" this one.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    int
    hashCode()
    Returns a hash code value for this object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

  • Constructor Details

    • 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 Details

    • 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.

    • from

      public static VMOption from(CompositeData cd)
      Returns a VMOption object represented by the given CompositeData. The given CompositeData must contain the following attributes:
      description
      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.