Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Class ActivationID - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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java.rmi.activation
Class ActivationID

java.lang.Object
  |
  +--java.rmi.activation.ActivationID

public class ActivationID
extends Object
implements Serializable

Activation makes use of special identifiers to denote remote objects that can be activated over time. An activation identifier (an instance of the class ActivationID) contains several pieces of information needed for activating an object:

a remote reference to the object's activator, and
a unique identifier for the object.

An activation id for an object can be obtained by registering an object with the activation system. Registration is accomplished in a few ways:

via the Activatable.register method
via the first Activatable constructor (that takes three arguments and both registers and exports the object, and
via the first Activatable.exportObject method that takes the activation descriptor, object and port as arguments; this method both registers and exports the object.

Since:: JDK1.2
See Also:: Activatable, Serialized Form

Constructor Summary

ActivationID(Activator activator)
          The constructor for ActivationID takes a single argument, activator, that specifies a remote reference to the activator responsible for activating the object associated with this identifier.

Method Summary

Remote activate(boolean force)
          Activate the object for this id.

boolean equals(Object obj)
          Compares two activation ids for content equality.

int hashCode()
          Returns a hashcode for the activation id.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ActivationID

public ActivationID(Activator activator)

The constructor for ActivationID takes a single argument, activator, that specifies a remote reference to the activator responsible for activating the object associated with this identifier. An instance of ActivationID is globally unique.

Parameters:: activator - reference to the activator responsible for activating the object
Since:: JDK1.2

Method Detail

activate

public Remote activate(boolean force)
                throws ActivationException,
                       UnknownObjectException,
                       RemoteException

Activate the object for this id.

Parameters:: force - if true, forces the activator to contact the group when activating the object (instead of returning a cached reference); if false, returning a cached value is acceptable.
Returns:: the reference to the active remote object
Throws:: ActivationException - if activation fails; UnknownObjectException - if the object is unknown; RemoteException - if remote call fails
Since:: JDK1.2

hashCode

public int hashCode()

Returns a hashcode for the activation id. Two identifiers that refer to the same remote object will have the same hash code.

Overrides:: hashCode in class Object

Since:: JDK1.2
See Also:: Hashtable

equals

public boolean equals(Object obj)

Compares two activation ids for content equality. Returns true if both of the following conditions are true: 1) the unique identifiers equivalent (by content), and 2) the activator specified in each identifier refers to the same remote object.

Overrides:: equals in class Object

Parameters:: obj - the Object to compare with
Returns:: true if these Objects are equal; false otherwise.
Since:: JDK1.2
See Also:: Hashtable