Exporter
), obtaining a proxy from an exported remote
object (ProxyAccessor
), obtaining the
server-side context information for an executing remote call (ServerContext
), and defining export permissions
(ExportPermission
).See: Description
Interface | Description |
---|---|
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.
|
ProxyAccessor |
Provides a means to obtain a proxy from an exported remote object.
|
ServerContext.Spi |
Defines the interface for server context providers, which are
consulted by
ServerContext.getServerContext() if no server context
has been explicitly associated with the current thread via a previous
call to ServerContext.doWithServerContext(java.lang.Runnable, java.util.Collection) . |
ServiceAttributesAccessor |
Provides a means to obtain
|
ServiceCodebaseAccessor |
After authenticating a bootstrap token proxy, the ProxyPreparer can
dynamically grant DownloadPermission and DeSerializationPermission
as required using the information provided, to allow downloading
of a smart proxy.
|
ServiceIDAccessor | |
ServiceProxyAccessor |
Provides a means to obtain a client-side proxy from a
"base" service object.
|
Class | Description |
---|---|
ExportPermission |
Defines runtime permissions for
Exporter implementations. |
ServerContext |
The
ServerContext class contains static methods to
execute some action within an appropriate server context for the
current thread and to obtain the server context for the current thread. |
Exception | Description |
---|---|
NoSuchObjectException |
A
NoSuchObjectException is thrown if an attempt is made to
invoke a method on an object that no longer exists in the remote virtual
machine. |
Exporter
), obtaining a proxy from an exported remote
object (ProxyAccessor
), obtaining the
server-side context information for an executing remote call (ServerContext
), and defining export permissions
(ExportPermission
). These abstractions are
independent of communication protocols, remote invocation semantics,
and other details of remote object behavior.
Exporter
abstraction is intended to satisfy the
following requirements:
The interface Exporter
is a
high-level API for both exporting a single remote object so
that it can receive remote method invocations, and unexporting
that same remote object. Applications can use a Configuration
provider together with
the Exporter
interface to export remote objects in a way
that can be configured and deployed at run-time to use specific
implementations of the Exporter
interface. See the net.jini.config
package documentation for examples on configurable exporting.
Several implementations of the Exporter
interface are provided:
JrmpExporter
Exports an object using the Java(TM) Remote Method Invocation (Java RMI) implementation in Java 2, SDK, Standard Edition (J2SE(TM)). The behavior of remote objects exported via a JrmpExporter
are the same as the behavior of objects exported via equivalentexportObject
methods of thejava.rmi.server.UnicastRemoteObject
andjava.rmi.activation.Activatable
classes.IiopExporter
Exports an object using the Java Remote Method Invocation over Internet-ORB Protocol technology (RMI-IIOP) in J2SE. The behavior of remote objects exported via an IiopExporter
are the same as the behavior of objects exported via theexportObject
method of the classjavax.rmi.PortableRemoteObject
and (where appropriate) connected to anORB
via theconnect
method ofjavax.rmi.CORBA.Stub
.BasicJeriExporter
Exports an object to use Jini extensible remote invocation (Jini ERI). A remote object exported with BasicJeriExporter
can have associated custom remote invocation and dispatch behavior, as well as a customized communication protocol.
The details of export and unexport behavior, including
communication protocols used for remote invocation and additional
invocation semantics, are defined by the particular implementation of
the Exporter
interface.
To export a remote object, an application needs to either construct
a new instance of an Exporter
implementation explicitly
or use the Configuration.getEntry
method to obtain a new
instance of an Exporter
implementation. It is preferable
to obtain exporters via the Configuration
provider
because doing so eliminates application code dependency on specific
Exporter
implementations. Only a single object can be
exported per Exporter
instance. Since an exporter hides
all the details of export behavior (for example, an object or
activation identifier) and such information in many cases is only
applicable to a single object, it simplifies the abstraction and the
programming model to require a new exporter per export.
The export
method exports a remote object and returns
a proxy that implements all the remote interfaces of the remote object
and that can be used to invoke remote methods on that exported remote
object. The caller should not make any assumptions about the behavior
of the Exporter
implementation to which the object was
exported, the implementation of the returned proxy (for example, it
need not be a "stub" class as defined in the Java RMI specification), or
the communication protocols used by the returned proxy to invoke
remote methods.
A remote object exported via a given Exporter
instance
can later be unexported by invoking the unexport
method
of that Exporter
instance.
ProxyAccessor
The interface ProxyAccessor
provides a
means to obtain a proxy for an exported remote object and is typically
used in conjunction with activatable remote objects. An activatable
remote object should implement this interface so that the activation
group can obtain the remote object's proxy once the remote object is
created (activated) and exported. If an activatable remote object
does not implement this interface, it must define a constructor that
takes as arguments an ActivationID
and a
MarshalledObject
, and it must be serializable and
marshalling the object produces a suitable proxy for the remote
object.
ServerContext
The class ServerContext
provides a generic API for associating and obtaining server context
information for a remote call executing in the current thread.
The class contains static methods for obtaining the server context for
the current thread (ServerContext.getServerContext
) and
for executing some action within a given server context
(ServerContext.doWithServerContext
). In addition, the
ServerContext
class provides the interface ServerContext.Spi
for server context
providers that are consulted to obtain a server context if one is not
already associated with the current thread via the
ServerContext.doWithServerContext
method.
The context information available from a given element of the collection is determined by that element's type. Examples of types that a given element might implement include:
A remote object does not itself set up a ServerContext
,
rather the Exporter
implementation that
dispatches incoming calls to its exported remote objects may establish
one for each call that it services.
For supplying context information for remote method execution, the
BasicJeriExporter
implementation uses the method
doWithServerContext
and the JrmpExporter
implementation uses the provider interface
ServerContext.Spi
. The IiopExporter
implementation does not support the ServerContext
API in
supplying context information for incoming calls dispatched to its
exported objects.
ExportPermission
The class ExportPermission
defines runtime permissions associated with export-related
operations. When invoking AbstractILFactory.getInvocationDispatcherMethods(java.rmi.Remote)
, the calling
context must have been granted the permission
ExportPermission("exportRemoteInterface.interfaceName")
for each non-public remote interface the supplied remote object
implements.
Copyright 2007-2013, multiple authors.
Licensed under the Apache License, Version 2.0, see the NOTICE file for attributions.