net.jini.export

Interface Exporter

All Known Implementing Classes:

ActivationExporter, BasicJeriExporter, IiopExporter, JrmpExporter, ProxyTrustExporter

public interface Exporter

An abstraction for exporting a single remote object such that it can receive remote method invocations, and later for unexporting that same remote object.

Details of the export and unexport behavior, including the communication protocols used for remote invocation and additional remote invocation semantics, are defined by the particular implementation of this interface.

Since:

2.0

Author:

Sun Microsystems, Inc.

Method Summary

Modifier and Type	Method and Description
Remote	export(Remote impl) Exports the specified remote object and returns a proxy that can be used to invoke remote methods on the exported remote object.
boolean	unexport(boolean force) Unexports the remote object that was exported by this Exporter such that it will no longer receive remote method invocations that were made possible as a result of exporting it with this Exporter.

Method Detail

export

Remote export(Remote impl)
       throws ExportException

Exports the specified remote object and returns a proxy that can be used to invoke remote methods on the exported remote object. This method must only be invoked once on a given Exporter instance.

The returned proxy implements an implementation-specific set of remote interfaces of the remote object and may also implement additional implementation-specific interfaces.

A remote interface is an interface that extends the interface java.rmi.Remote and whose methods each declare at least one exception whose type is java.rmi.RemoteException or one of its superclasses.

This method should not be called from within an object constructor, otherwise the object reference will escape during construction, leaving the remote object implementation in an undefined state.

Parameters:

impl - a remote object to export

Returns:

a proxy for the remote object

Throws:

ExportException - if a problem occurs exporting the object

SecurityException - if a SecurityException occurs exporting the object

NullPointerException - if impl is null

IllegalStateException - if an object has already been exported with this Exporter instance

See Also:

Startable

unexport

boolean unexport(boolean force)

Unexports the remote object that was exported by this Exporter such that it will no longer receive remote method invocations that were made possible as a result of exporting it with this Exporter. The unexport operation may not occur if the force argument is false. This method must only be invoked after the export method has been invoked on this Exporter instance to export a remote object successfully.

This method returns true if upon return, the remote object is no longer exported with this Exporter, and false if the remote object remains exported with this Exporter. This method will always return true if it has returned true previously.

The force parameter serves to indicate whether or not the caller desires the unexport to occur even if there are known remote calls pending or in progress to the remote object that were made possible by this Exporter:

• If force is true, then the remote object will be forcibly unexported even if there are remote calls pending or in progress, and this method will return true.
• If force is false, then this acts as a hint to the implementation that the remote object should not be unexported if there are known remote calls pending or in progress, and this method will either unexport the remote object and return true or not unexport the remote object and return false. If the implementation detects that there are indeed remote calls pending or in progress, then it should return false; otherwise, it must return true. If the implementation does not support being able to unexport conditionally based on knowledge of remote calls pending or in progress, then it must implement this method as if force were always true.

If the remote object is unexported as a result of this method, then the implementation may (and should, if possible) prevent remote calls in progress from being able to communicate their results successfully.

Parameters:

force - if true, the remote object will be unexported even if there are remote calls pending or in progress; if false, the remote object may only be unexported if there are no known remote calls pending or in progress

Returns:

true if the remote object is unexported when this method returns and false otherwise

Throws:

IllegalStateException - if an object has not been exported with this Exporter instance