Utility class used to export/unexport an activatable remote object to/from the RMI system using
Activatable.
This utility may be used if either of the following conditions apply:
a remote object implementation cannot subclass a standard remote object implementation such
as UnicastRemoteObject because it is required to extend a different
superclass.
one desires to be able to selectively control whether or not a remote object implementation
needs to service remote callers or if it is just being used to service local calls.
*
Constructor Examples
This section presents examples that
show how to construct an activatable remote object exporter.
Example 1 : Default socket factories and an anonymous port
Example 2 : Specified socket factories and an anonymous port
Example 4 : Specified socket factories, port and forcible unexport
preference
Example 1: Construct an Exporter Using Default Socket Factories and
an Anonymous Port
The following code example shows how construct an exporter using default
RMI socket factories and an anonymous port.
import java.rmi.Remote;
import java.rmi.RemoteException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
import com.sas.net.rmi.ActivatableObjectExporter;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
public SomeActivatableObjectImplementation ()
throws RemoteException {
super();
...
// construct an activatable object exporter using:
// - anonymous port
// - default RMI socket factories
// - preference to forcibly unexport the remote object
// - activation ID
boolean isForcibleUnexport = false;
_rmiExporter = new ActivatableObjectExporter(
this, // the remote object to be exported
Constants.PORT_ANONYMOUS, // export remote object on an anonymous port
null, // default RMI client socket factory
null, // use default RMI server socket factory
isForcibleUnexport, // do not forcibly unexport the remote object
activationID); // activation ID obtained from a previous export
// export the remote object to the RMI system.
// a RemoteException will be thrown if the export fails.
Remote exportedRemoteObject = _rmiExporter.export();
}
}
Example 2: Construct an Exporter Using Specified Socket
Factories and an Anonymous Port
The following code example shows how construct an exporter
by specifying desired RMI socket factories and an anonymous port.
import java.rmi.Remote;
import java.rmi.RemoteException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
import com.sas.net.rmi.ActivatableObjectExporter;
import com.sas.net.ssl.SSLRMISocketFactories;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
public SomeRemoteObjectImplementation ()
throws RemoteException {
super();
...
// construct a unicast remote object exporter using:
// - anonymous port
// - specified RMI socket factories
// - preference to forcibly unexport the remote object
// - activation ID
SSLRMISocketFactories sslRMISocketFactories =
SSLRMISocketFactories.getInstance();
Class theClass = getClass();
RMIClientSocketFactory rmiClientSocketFactory =
sslRMISocketFactories.getRMIClientSocketFactoryForClass(theClass);
RMIServerSocketFactory rmiServerSocketFactory =
sslRMISocketFactories.getRMIServerSocketFactoryForClass(theClass);
boolean isForcibleUnexport = false;
_rmiExporter = new ActivatableObjectExporter(
this, // the remote object to be exported
Constants.PORT_ANONYMOUS, // export remote object on an anonymous port
rmiClientSocketFactory, // RMI client socket factory
rmiServerSocketFactory, // RMI server socket factory
isForcibleUnexport, // do not forcibly unexport the remote object
activationID); // activation ID obtained from a previous export
// export this remote object to the RMI system.
// RemoteException will be thrown if the export fails.
Remote exportedRemoteObject = _rmiExporter.export();
}
}
Example 3: Construct an Exporter Using Specified Socket Factories and
Port
The following code example shows how construct an exporter by specifying desired RMI
socket factories and port.
import java.rmi.Remote;
import java.rmi.RemoteException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
import com.sas.net.rmi.ActivatableObjectExporter;
import com.sas.net.ssl.SSLRMISocketFactories;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
public SomeRemoteObjectImplementation ()
throws RemoteException {
super();
// construct a unicast remote object exporter using:
// - specified port
// - specified RMI socket factories
// - preference to forcibly unexport the remote object
// - activation ID
SSLRMISocketFactories sslRMISocketFactories =
SSLRMISocketFactories.getInstance();
Class theClass = getClass();
RMIClientSocketFactory rmiClientSocketFactory =
sslRMISocketFactories.getRMIClientSocketFactoryForClass(theClass);
RMIServerSocketFactory rmiServerSocketFactory =
sslRMISocketFactories.getRMIServerSocketFactoryForClass(theClass);
int portNumber = 8216;
boolean isForcibleUnexport = false;
_rmiExporter = new ActivatableObjectExporter(
this, // the remote object to be exported
portNumber, // port on which to export the remote object
rmiClientSocketFactory, // RMI client socket factory
rmiServerSocketFactory, // RMI server socket factory
isForcibleUnexport, // do not forcibly unexport the remote object
activationID); // activation ID obtained from a previous export
// export this remote object to the RMI system.
// RemoteException will be thrown if the export fails.
Remote exportedRemoteObject = _rmiExporter.export();
}
}
Example 4: Construct an Exporter Using Specified Socket
Factories, Port and Forcible Unexport Preference
The following code example shows how
construct an exporter by specifying desired RMI socket factories, port, and forcible unexport
preference.
import java.rmi.Remote;
import java.rmi.RemoteException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
import com.sas.net.rmi.ActivatableObjectExporter;
import com.sas.net.ssl.SSLRMISocketFactories;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
public SomeRemoteObjectImplementation ()
throws RemoteException {
super();
// construct a unicast remote object exporter using:
// - specified port
// - specified RMI socket factories
// - preference to forcibly unexport the remote object
// - activation ID
SSLRMISocketFactories sslRMISocketFactories =
SSLRMISocketFactories.getInstance();
Class theClass = getClass();
RMIClientSocketFactory rmiClientSocketFactory =
sslRMISocketFactories.getRMIClientSocketFactoryForClass(theClass);
RMIServerSocketFactory rmiServerSocketFactory =
sslRMISocketFactories.getRMIServerSocketFactoryForClass(theClass);
int portNumber = 8216;
boolean isForcibleUnexport = true;
_rmiExporter = new ActivatableObjectExporter(
this, // the remote object to be exported
portNumber, // port on which to export the remote object
rmiClientSocketFactory, // RMI client socket factory
rmiServerSocketFactory, // RMI server socket factory
isForcibleUnexport, // do not forcibly unexport the remote object
activationID); // activation ID obtained from a previous export
// export this remote object to the RMI system.
// RemoteException will be thrown if the export fails.
Remote exportedRemoteObject = _rmiExporter.export();
}
}
Export/Unexport Examples
This section presents code examples detailing how to
export and unexport a remote object.
The following code example shows
how to export a remote object.
import java.rmi.Remote;
import java.rmi.RemoteException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
import com.sas.net.rmi.ActivatableObjectExporter;
import com.sas.net.ssl.SSLRMISocketFactories;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
public SomeRemoteObjectImplementation ()
throws RemoteException {
super();
// construct a unicast remote object exporter
// using specified socket factories and an
// anonymous port
SSLRMISocketFactories sslRMISocketFactories =
SSLRMISocketFactories.getInstance();
Class theClass = getClass();
RMIClientSocketFactory rmiClientSocketFactory =
sslRMISocketFactories.getRMIClientSocketFactoryForClass(theClass);
RMIServerSocketFactory rmiServerSocketFactory =
sslRMISocketFactories.getRMIServerSocketFactoryForClass(theClass);
int portNumber = 1099;
boolean isForcibleUnexport = true;
_rmiExporter = new ActivatableObjectExporter(
this, // the remote object to be exported
portNumber, // port on which to export the remote object
rmiClientSocketFactory, // RMI client socket factory
rmiServerSocketFactory, // RMI server socket factory
isForcibleUnexport, // do not forcibly unexport the remote object
activationID); // activation ID obtained from a previous export
// export the remote object to the RMI system
// throws a RemoteException if unable to export the remote object.
Remote exportedRemoteObject = _rmiExporter.export();
}
}
Example 6: Unexport Remote Object
The following code
example shows how to unexport a remote object.
import java.rmi.NoSuchObjectException;
import com.sas.net.rmi.RemoteObjectExporterInterface;
...
public SomeActivatableObjectImplementation ()
implements SomeActivatableInterface {
private RemoteObjectExporterInterface _rmiExporter;
...
public destroy () {
...
if (_rmiExporter.isExported()) {
try {
// unexport the remote object from the RMI system
// note that the remote object will be unexported
// forcibly (terminating active and refusing pending calls) if the
// preference is to forcibly unexport
boolean wasUnexported = _rmiExporter.unexport();
if (!wasUnexported) {
// if a non-forcible unexport was specified, then
// the remote object may still be servicing calls.
// forcibly unexport or try again later
}
}
catch (NoSuchObjectException) {
// log an error
}
}
}
}
Constructs an instance of an activatable exporter for the specified remote object, activation
ID, and port number using specified socket factories.
Parameters:
remoteObject - The remote object that may be exported to the RMI system to create a
remote object stub.
activationId - Activation ID
portNumber - Port on which the object should be exported. Specify
Constants.PORT_ANONYMOUS to designate an anonymous port or a value greater
than 0 to designate a well-known port.
rmiClientSocketFactory - The client-side RMI socket factory is used to create sockets to
make calls to the remote object or null if using the default.
rmiServerSocketFactory - The server-side RMI socket factory is used to create sockets to
receive remote calls or null if using the default.
isForcibleUnexport - Specify true if the remote object should be unexported
without regard to whether or not there are any active or pending remote calls or
false if the remote object should not be unexported if there are
active or pending calls.
Exports the remote object returning the remote object's stub.
This method is called by AbstractRemoteObjectExporter.exportObject() to export a
unicast remote object stub. This method provides the concrete implementation of a template
method used to unexport a remote object stub using
Activatable.exportObject(Remote, ActivationID, int, RMIClientSocketFactory, RMIServerSocketFactory)
.
remoteObject - The remote object that may be exported to the RMI system to create a
remote object stub. Ensure that the remote object implementation correctly
implements hashCode,
equals, and toString methods to ensure correct behavior by the remote object.
portNumber - Port on which the object should be exported. Specify
Constants.PORT_ANONYMOUS to designate an anonymous port or a value greater
than 0 to designate a well-known port.
rmiClientSocketFactory - The client-side RMI socket factory is used to create sockets to
make calls to the remote object or null if using the default.
rmiServerSocketFactory - The server-side RMI socket factory is used to create sockets to
receive remote calls or null if using the default.
Returns:
Exported remote object's stub. The stub will always be non-null.
exportedRemoteObjectStub - The remote object's stub which is to be removed from the RMI
system. This is the stub which was obtained from the AbstractRemoteObjectExporter.exportObject() call.
isForcibleUnexport - true if the remote object's stub should be forcibly
removed from the RMI system without regard to whether or not there are any active
or pending calls. Specify false if the stub should not be unexported
if there are active or pending calls.
Returns:
true if the exported remote object's stub was successfully unexported
from the RMI system.
