Distributed computing – putting it all together - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 555

After the registry has been created, we continue as in Chapter 18 by instantiating
a ServerFactory object and binding it into the registry under the name in the
FACTORY - NAME constant:
try {
ServerFactory factory = new ServerFactory ();
Naming.rebind ("//localhost:" + port + "/" + FACTORY - NAME,
factory);
System.out.println(
" \ n READY AND WAITING ON CLIENTS ON PORT " + port);
}
As usual we must catch the following exceptions:
catch (MalformedURLException mue) {
System.err.println (mue);
System.exit (1);
}
catch (RemoteException re) {
System.err.println (re);
System.err.println (" \ n EXITING BECAUSE OF FAILURE");
System.exit (1);
}
20.4.2 Implementing getInstance()
Our getInstance() implementation receives the ID parameter and returns an
object that implements ServerInterface :
public ServerInterface getInstance (String id)
throws RemoteException
{ ... }
For this example, we simply create a Server object for return. We haven't yet
discussed the Server implementation, and although we know the signatures of
the methods it must contain (since it must implement ServerInterface ), we
don't yet know how to call its constructor. Often, implementations evolve through
an iterative process, so let's start by calling the constructor as follows:
ServerInterface server = new Server (id);
Our getInstance() needs to return a ServerInterface , not a Server
object, so we declare the object returned by the Server constructor to be of type
ServerInterface . (It is, in fact, a Server object, but since it implements
ServerInterface ,itisalso of type ServerInterface .)
As shown, we also passed the id value received by getInstance() to
the Server constructor. From the discussion above, the ID parameter serves to