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Préférences
Moteurs de recherche
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JavaTM 2 Platform Std. Ed. v1.6.0
java.rmi.activation
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Method Summary | |
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MarshalledObject<? extends Remote> |
activate(ActivationID id,
boolean force)
Activate the object associated with the activation identifier, id . |
Method Detail |
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MarshalledObject<? extends Remote> activate(ActivationID id, boolean force) throws ActivationException, UnknownObjectException, RemoteException
id
. If the activator knows the object to be active
already, and force
is false , the stub with a
"live" reference is returned immediately to the caller;
otherwise, if the activator does not know that corresponding
the remote object is active, the activator uses the activation
descriptor information (previously registered) to determine the
group (VM) in which the object should be activated. If an
ActivationInstantiator
corresponding to the
object's group descriptor already exists, the activator invokes
the activation group's newInstance
method passing
it the object's id and descriptor.
If the activation group for the object's group descriptor does
not yet exist, the activator starts an
ActivationInstantiator
executing (by spawning a
child process, for example). When the activator receives the
activation group's call back (via the
ActivationSystem
's activeGroup
method) specifying the activation group's reference, the
activator can then invoke that activation instantiator's
newInstance
method to forward each pending
activation request to the activation group and return the
result (a marshalled remote object reference, a stub) to the
caller.
Note that the activator receives a "marshalled" object instead of a Remote object so that the activator does not need to load the code for that object, or participate in distributed garbage collection for that object. If the activator kept a strong reference to the remote object, the activator would then prevent the object from being garbage collected under the normal distributed garbage collection mechanism.
id
- the activation identifier for the object being activatedforce
- if true, the activator contacts the group to obtain
the remote object's reference; if false, returning the cached value
is allowed.
ActivationException
- if object activation fails
UnknownObjectException
- if object is unknown (not registered)
RemoteException
- if remote call fails