framedresource.java

很棒的web服务器源代码

     * @param cls The class of frames we are looking for.
     * @param identifier the frame identifier
     * @return a ResourceFrame instance of <strong>null</strong>
     */
    ResourceFrame unsafeGetFrame(Class c, String identifier) {
	ResourceFrame frames[] = collectFrames(c);
	if (frames != null) {
	    for (int i = 0 ; i < frames.length ; i++) {
		ResourceFrame fr = frames[i];
		if (fr.getIdentifier().equals(identifier))
		    return fr;
	    }
	}
	return null;
    }

    /**
     * Get the frame of the given class.
     * @param classname the class name
     * @return a ResourceFrame instance of null.
     */
    public synchronized ResourceFrame getFrame(String classname) {
	try {
	    Class c = Class.forName(classname);
	    return getFrame(c);
	} catch (Exception ex) {
	    return null;
	}
    }

    /**
     * (AWT Like), dspatch the Event to all our listeners.
     * @param evt The resourceEvent to dispatch.
     */
    public void processEvent(ResourceEvent evt) {
	if (evt instanceof StructureChangedEvent) {
	    fireStructureChangedEvent((StructureChangedEvent)evt);
	} else if (evt instanceof AttributeChangedEvent) {
	    fireAttributeChangeEvent((AttributeChangedEvent)evt);
	}
    }

    /**
     * Post an Event in the Event Queue.
     * @param evt The Event to post.
     */
    public void postEvent(ResourceEvent evt) {
	if (eventDisabled())
	    return;
	ResourceSpace space = getSpace();
	if (space != null) 
	    space.getEventQueue().sendEvent(evt);
    }

    /**
     * Add an attribute change listener.
     * @param l The new attribute change listener.
     */

    public void addAttributeChangedListener(AttributeChangedListener l) {
	attrListener = ResourceEventMulticaster.add(attrListener, l);
    }

    /**
     * Remove an attribute change listener.
     * @param l The listener to remove.
     */

    public void removeAttributeChangedListener(AttributeChangedListener l) {
	attrListener = ResourceEventMulticaster.remove(attrListener, l);
    }

    /**
     * post an attribute change event. Actually this kind of event should 
     * not be posted. So fire them!
     * @param idx The index of the attribute that has changed.
     * @param newvalue The new value for that attribute.
     */

    protected void postAttributeChangeEvent(int idx, Object newvalue) {
	if (eventDisabled())
	    return;
	if (( attrListener != null ) && (getResourceReference() != null)) {
	    AttributeChangedEvent evt = 
		new AttributeChangedEvent(getResourceReference(),
					  attributes[idx],
					  newvalue);
	    fireAttributeChangeEvent(evt);
	}
    }

    /**
     * Fire an attribute change event.
     * @param evt the AttributeChangedEvent to fire.
     */
    protected void fireAttributeChangeEvent(AttributeChangedEvent evt) {
	if ( attrListener != null )
	    attrListener.attributeChanged(evt);
    }

    /**
     * Add a structure change listener.
     * @param l The new structure change listener.
     */

    public void addStructureChangedListener(StructureChangedListener l) {
	structListener = ResourceEventMulticaster.add(structListener, l);
    }

    /**
     * Remove a structure change listener.
     * @param l The listener to remove.
     */

    public void removeStructureChangedListener(StructureChangedListener l) {
	structListener = ResourceEventMulticaster.remove(structListener, l);
    }

    /**
     * post an structure change event.
     * @param rr the ResourceReference of the source.
     * @param type The type of the event.
     */
    protected void postStructureChangedEvent(ResourceReference rr, int type) {
	if ((structListener != null) && (rr != null)) {
	    StructureChangedEvent evt = 
		new StructureChangedEvent(rr, type);
	    postEvent(evt);
	}
    }

    /**
     * post an structure change event.
     * @param type The type of the event.
     */
    protected void postStructureChangedEvent(int type) {
	if ((structListener != null) && (getResourceReference() != null)) {
	    StructureChangedEvent evt = 
		new StructureChangedEvent(getResourceReference(), type);
	    postEvent(evt);
	}
    }

    /**
     * Fire an structure change event.
     * @param type The type of the event.
     */
    protected void fireStructureChangedEvent(int type) {
	if ((structListener != null) && (getResourceReference() != null)) {
	    StructureChangedEvent evt = 
		new StructureChangedEvent(getResourceReference(), type);
	    fireStructureChangedEvent(evt);
	}
    }

    /**
     * Fire an structure change event.
     * @param evt the StructureChangedEvent to fire.
     */
    protected void fireStructureChangedEvent(StructureChangedEvent evt) {
	if (structListener != null) {
	    int type = evt.getID();
	    switch (type) {
	    case Events.RESOURCE_MODIFIED :
		structListener.resourceModified(evt);
		break;
	    case Events.RESOURCE_CREATED :
		structListener.resourceCreated(evt);
		break;
	    case Events.RESOURCE_REMOVED :
		structListener.resourceRemoved(evt);
		break;
	    case Events.RESOURCE_UNLOADED :
		structListener.resourceUnloaded(evt);
		break;
	    }
	}
    }

    /**
     * This resource is being unloaded.
     * The resource is being unloaded from memory, perform any additional
     * cleanup required.
     */
    public void notifyUnload() {
	//
	// direct notification
	//
	ResourceFrame frames[] = getFrames();
	if ( frames != null ) {
	    for (int i = 0 ; i < frames.length ; i++) {
		if ( frames[i] == null )
		    continue;
		frames[i].notifyUnload();
	    }
	}
	fireStructureChangedEvent(Events.RESOURCE_UNLOADED);
	super.notifyUnload();
    }

    /**
     * Delete this Resource instance, and remove it from its store.
     * This method will erase definitely this resource, for ever, by removing
     * it from its resource store (when doable).
     * @exception MultipleLockException if someone has locked this resource.
     */
    public synchronized void delete() 
	throws MultipleLockException 
    {
	disableEvent();
	// fire and not post because we don't want this resource
	// to be locked() during the delete.
	fireStructureChangedEvent(Events.RESOURCE_REMOVED);
	ResourceFrame frames[] = getFrames();
	if ( frames != null ) {
	    for (int i = 0 ; i < frames.length ; i++) {
		if ( frames[i] == null )
		    continue;
		frames[i].removeFrameEventListener(this);
		this.removeAttributeChangedListener(frames[i]);
		frames[i].unregisterResource(this);
	    }
	}
	try {
	    super.delete();
	} catch (MultipleLockException ex) {
	    enableEvent();
	    throw ex;
	}
    }

    /**
     * Mark this resource as having been modified.
     */
    public void markModified() {
	super.markModified();
	postStructureChangedEvent(Events.RESOURCE_MODIFIED);
    }

    /**
     * Set some of this resource attribute. We overide setValue to post
     * events.
     */
    public synchronized void setValue(int idx, Object value) {
	super.setValue(idx, value) ;
	if (idx != ATTR_LAST_MODIFIED) {
	    postAttributeChangeEvent(idx, value);
	    postStructureChangedEvent(Events.RESOURCE_MODIFIED);
	}
    }

    /**
     * Set a value, without posting event.
     * @param idx The attribute index, in the list of attributes advertized by 
     * the resource.
     * @param value The new value for this attribute.
     */
    public synchronized void setSilentValue(int idx, Object value) {
	disableEvent();
	super.setValue(idx, value);
	enableEvent();
    }

    /**
     * Set a value, without posting event.
     * @param name The attribute name.
     * @param value The new value for the attribute.
     */
    public synchronized void setSilentValue(String name, Object value) {
	disableEvent();
	super.setValue(name, value);
	enableEvent();
    }

    /**
     * Lookup the target resource.
     * @param ls The current lookup state
     * @param lr The result
     * @return true if lookup is done.
     * @exception ProtocolException If an error relative to the protocol occurs
     */
    public boolean lookup(LookupState ls, LookupResult lr) 
	throws ProtocolException
    {
	ResourceFrame frames[] = getFrames();
	if (frames != null) {
	    for (int i = 0 ; i < frames.length ; i++) {
		if (frames[i] == null)
		    continue;
		if (frames[i].lookup(ls,lr))
		    return true;
	    }
	}
	if ( ls.hasMoreComponents() ) {
	    // We are not a container resource, and we don't have children:
	    lr.setTarget(null);
	    return false;
	} else {
	    //we are done!
	    lr.setTarget(getResourceReference());
	    return true;
	}
    }

    /**
     * Perform the request on all the frames of that resource. The
     * Reply returned is the first non-null reply.
     * @param request A RequestInterface instance.
     * @return A ReplyInterface instance.
     * @exception ProtocolException If an error relative to the protocol occurs
     * @exception ResourceException If an error not relative to the 
     * protocol occurs
     */
    protected ReplyInterface performFrames(RequestInterface request) 
	throws ProtocolException, ResourceException
    {
	ResourceFrame frames[] = getFrames();
	if (frames != null) {
	    for (int i = 0 ; i < frames.length ; i++) {
		if (frames[i] == null)
		    continue;
		ReplyInterface reply  = frames[i].perform(request);
		if (reply != null)
		    return reply;
	    }
	}
	return null;
    }

    /**
     * Perform the request.
     * @return a ReplyInterface instance
     * @exception ProtocolException If an error relative to the protocol occurs
     * @exception ResourceException If an error not relative to the 
     * protocol occurs
     */
    public ReplyInterface perform(RequestInterface request) 
	throws ProtocolException, ResourceException
    {
	return performFrames(request);
    }

    /**
     * Initialize the frames of that framed resource.
     * @param values Default attribute values.
     */

    public void initialize(Object values[]) {
	this.attrListener   = null;
	this.structListener = null;
	disableEvent();
	super.initialize(values);
	// Initialize the frames if any.
	ResourceFrame frames[] = getFrames();
	if ( frames != null ) {
	    this.framesRef = new Hashtable(Math.max(frames.length, 1));
	    Hashtable defs = new Hashtable(3);
	    for (int i = 0 ; i < frames.length ; i++) {
		if ( frames[i] == null )
		    continue;
		frames[i].registerResource(this);
		frames[i].initialize(defs);
		frames[i].addFrameEventListener(this);
		this.addAttributeChangedListener(frames[i]);
	    }
	} else {
	    this.framesRef = new Hashtable(3);
	}
	enableEvent();
    }

}