MudServerpublic class MudServer extends UnicastRemoteObject implements RemoteMudServer, Serializable| This class implements the RemoteMudServer interface. It also defines a
main() method so you can run it as a standalone program that will
set up and initialize a MUD server. Note that a MudServer maintains an
entrance point to a MUD, but it is not the MUD itself. Most of the
interesting MUD functionality is defined by the RemoteMudPlace interface
and implemented by the RemotePlace class. In addition to being a remote
object, this class is also Serializable, so that the state of the MUD
can be saved to a file and later restored. Note that the main() method
defines two ways of starting a MUD: one is to start it from scratch with
a single initial place, and another is to restore an existing MUD from a
file. |
| Fields Summary |
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| MudPlace | entrance | | String | password | | String | mudname | | Hashtable | places | | static final long | serialVersionUIDThis constant is a version number for serialization |
| Constructors Summary |
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public MudServer(String mudname, String password, String placename, String description)Start a MUD from scratch, with the given name and password. Create
an initial MudPlace object as the entrance, giving it the specified
name and description.
this.mudname = mudname;
this.password = password;
this.places = new Hashtable();
// Create the entrance place
try { this.entrance = new MudPlace(this, placename, description); }
catch (PlaceAlreadyExists e) {} // Should never happen
| public MudServer()For serialization only. Never call this constructor.
|
| Methods Summary |
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| public void | dump(java.lang.String password, java.lang.String f)This remote method serializes and compresses the state of the MUD
to a named file, if the specified password matches the one specified
when the MUD was initially created. Note that the state of a MUD
consists of all places in the MUD, with all things and exits in those
places. The people in the MUD are not part of the state that is saved.
if ((this.password != null) && !this.password.equals(password))
throw new BadPassword();
ObjectOutputStream out =
new ObjectOutputStream(new GZIPOutputStream(new FileOutputStream(f)));
out.writeObject(this);
out.close();
| | public RemoteMudPlace | getEntrance()This remote method returns the entrance place of the MUD
return entrance;
| | public java.lang.String | getMudName()This remote method returns the name of the MUD return mudname;
| | public RemoteMudPlace | getNamedPlace(java.lang.String name)This remote method returns a RemoteMudPlace object for the named place.
In this sense, a MudServer acts as like an RMI Registry object, returning
remote objects looked up by name. It is simpler to do it this way than
to use an actual Registry object. If the named place does not exist,
it throws a NoSuchPlace exception
RemoteMudPlace p = (RemoteMudPlace) places.get(name);
if (p == null) throw new NoSuchPlace();
return p;
| | public static void | main(java.lang.String[] args)This main() method defines the standalone program that starts up a MUD
server. If invoked with a single argument, it treats that argument as
the name of a file containing the serialized and compressed state of an
existing MUD, and recreates it. Otherwise, it expects four command-line
arguments: the name of the MUD, the password, the name of the entrance
place for the MUD, and a description of that entrance place.
Besides creating the MudServer object, this program sets an appropriate
security manager, and uses the default rmiregistry to register the
the MudServer under its given name.
try {
MudServer server;
if (args.length == 1) {
// Read the MUD state in from a file
FileInputStream f = new FileInputStream(args[0]);
ObjectInputStream in = new ObjectInputStream(new GZIPInputStream(f));
server = (MudServer) in.readObject();
}
// Otherwise, create an initial MUD from scratch
else server = new MudServer(args[0], args[1], args[2], args[3]);
System.setSecurityManager(new RMISecurityManager());
Naming.rebind(Mud.mudPrefix + server.mudname, server);
}
// Display an error message if anything goes wrong.
catch (Exception e) {
System.out.println(e);
System.out.println("Usage: java MudServer <savefile>\n" +
" or: java MudServer <mudname> <password> " +
"<placename> <description>");
System.exit(1);
}
| | public void | setPlaceName(RemoteMudPlace place, java.lang.String name)Define a new placename to place mapping in our hashtable.
This is not a remote method. The MudPlace() constructor calls it
to register the new place it is creating.
if (places.containsKey(name)) throw new PlaceAlreadyExists();
places.put(name, place);
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