net.dpml.station.server
Class DefaultModel

java.lang.Object
  java.rmi.server.RemoteObject
      java.rmi.server.RemoteServer
          java.rmi.server.UnicastRemoteObject
              net.dpml.station.server.DefaultModel

All Implemented Interfaces:

Serializable, Remote

Direct Known Subclasses:

RemoteApplicationRegistry

public abstract class DefaultModel
extends UnicastRemoteObject

A abstract base class that established an event queue and handles event dispatch operations for listeners declared in classes extending this base class.

Version:

1.0.3

Author:

Digital Product Meta Library

See Also:

Serialized Form

Field Summary

Fields inherited from class java.rmi.server.RemoteObject

ref

Constructor Summary

DefaultModel(Logger logger)
Creation of a new model.

DefaultModel(String name)
Creation of a new model.

Method Summary

protected void	addListener(EventListener listener) Add a listener to the set of listeners handled by the model.
protected void	enqueueEvent(EventObject event) Enqueue an event for delivery to registered listeners unless there are no registered listeners.
protected void	enqueueEvent(EventObject event, boolean asynchronouse) Enqueue an event for delivery to registered listeners unless there are no registered listeners.
protected Object	getLock() Return the internal synchronization lock object.
protected Logger	getLogger() Return the assigned logging channel.
protected EventListener[]	listeners() Return the set of registered listeners.
protected abstract void	processEvent(EventObject event) Abstract method that must be implemented by classes extending this class.
protected void	removeListener(EventListener listener) Remove a listener to the set of listeners handled by this producer.

Methods inherited from class java.rmi.server.UnicastRemoteObject

clone, exportObject, exportObject, exportObject, unexportObject

Methods inherited from class java.rmi.server.RemoteServer

getClientHost, getLog, setLog

Methods inherited from class java.rmi.server.RemoteObject

equals, getRef, hashCode, toString, toStub

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DefaultModel

public DefaultModel(String name)
             throws RemoteException

Creation of a new model.

Parameters:

name - the name used to construct a logging channel

Throws:

RemoteException - if a remote exception occurs

DefaultModel

public DefaultModel(Logger logger)
             throws NullPointerException,
                    RemoteException

Creation of a new model.

Parameters:

logger - the assigned logging channel

Throws:

NullPointerException - if the supplied logging channel is null

RemoteException - if a remote exception occurs

Method Detail

processEvent

protected abstract void processEvent(EventObject event)

Abstract method that must be implemented by classes extending this class. An implementation is responsible for handling the processing of events it is aware of or throwing an llegalArgumentException in the case of unrecognized event types. A typical implementation is shown in the following code fragment:

 protected void processEvent( EventObject eventObject )
 {
    if( eventObject instanceof ProxyEvent )
    {
        ProxyEvent event = (ProxyEvent) eventObject;
        processProxyEvent( event );
    }
    else
    {
        final String error = 
          "Event class not recognized: " + eventObject.getClass().getName();
        throw new IllegalArgumentException( error );
    }
 }

 private void processProxyEvent( ProxyEvent event )
 {
    EventListener[] listeners = super.listeners();
    for( int i=0; i<listeners.length; i++ )
    {
        EventListener listener = listeners[i];
        if( listener instanceof ProxyListener )
        {
            ProxyListener pl = (ProxyListener) listener;
            try
            {
                pl.proxyChanged( event );
            }
            catch( Throwable e )
            {
                final String error =
                  "Proxy listener notification error.";
                getLogger().error( error, e );
            }
        }
    }
 }
 

Parameters:

event - the event to process

getLogger

protected Logger getLogger()

Return the assigned logging channel.

Returns:

the logging channel

addListener

protected void addListener(EventListener listener)
                    throws NullPointerException

Add a listener to the set of listeners handled by the model.

Parameters:

listener - the event listener

Throws:

NullPointerException - if the supplied listener is null

removeListener

protected void removeListener(EventListener listener)
                       throws NullPointerException

Remove a listener to the set of listeners handled by this producer.

Parameters:

listener - the event listener

Throws:

NullPointerException - if the supplied listener is null

getLock

protected Object getLock()

Return the internal synchronization lock object.

Returns:

the lock object

listeners

protected EventListener[] listeners()

Return the set of registered listeners.

Returns:

an array of registered listeners

enqueueEvent

protected void enqueueEvent(EventObject event)

Enqueue an event for delivery to registered listeners unless there are no registered listeners.

Parameters:

event - the event object to add to the queue

enqueueEvent

protected void enqueueEvent(EventObject event,
                            boolean asynchronouse)

Enqueue an event for delivery to registered listeners unless there are no registered listeners.

Parameters:

event - the event object to add to the queue

asynchronouse - TRUE if asynchronouse delivery