eventfilter.java

gcc的组建

	// We delegate through the "xxNext" handlers, and
	// report the "xxHandler" ones on our input side.

	// Normally a subclass would both override handler
	// methods and register itself as the "xxHandler".

	docHandler = docNext = consumer.getContentHandler ();
	dtdHandler = dtdNext = consumer.getDTDHandler ();
	try {
	    declHandler = declNext = (DeclHandler)
		    consumer.getProperty (DECL_HANDLER);
	} catch (SAXException e) { /* leave value null */ }
	try {
	    lexHandler = lexNext = (LexicalHandler)
		    consumer.getProperty (LEXICAL_HANDLER);
	} catch (SAXException e) { /* leave value null */ }
    }

    /**
     * Treats the XMLFilterImpl as a limited functionality event consumer,
     * by arranging to deliver events to it; this lets such classes be
     * "wrapped" as pipeline stages.
     *
     * <p> <em>Upstream Event Setup:</em>
     * If no handlers have been assigned to this EventFilter, then the
     * handlers from specified XMLFilterImpl are returned from this
     * {@link EventConsumer}: the XMLFilterImpl is just "wrapped".
     * Otherwise the specified handlers will be returned.
     *
     * <p> <em>Downstream Event Setup:</em>
     * Subclasses may chain event delivery to the specified XMLFilterImpl
     * by invoking the appropiate superclass methods,
     * as if their constructor passed a "next" EventConsumer to the
     * constructor for this class.
     * If this EventFilter has an ErrorHandler, it is assigned as
     * the error handler for the XMLFilterImpl, just as would be
     * done for a next stage implementing {@link EventConsumer}.
     *
     * @param next the next downstream component of the pipeline.
     * @exception IllegalStateException if the "next" consumer has
     *	already been set through the constructor.
     */
    public void chainTo (XMLFilterImpl next)
    {
	if (this.next != null)
	    throw new IllegalStateException ();

	docNext = next.getContentHandler ();
	if (docHandler == null)
	    docHandler = docNext;
	dtdNext = next.getDTDHandler ();
	if (dtdHandler == null)
	    dtdHandler = dtdNext;

	try {
	    declNext = (DeclHandler) next.getProperty (DECL_HANDLER);
	    if (declHandler == null)
		declHandler = declNext;
	} catch (SAXException e) { /* leave value null */ }
	try {
	    lexNext = (LexicalHandler) next.getProperty (LEXICAL_HANDLER);
	    if (lexHandler == null)
		lexHandler = lexNext;
	} catch (SAXException e) { /* leave value null */ }

	if (errHandler != null)
	    next.setErrorHandler (errHandler);
    }

    /**
     * Records the error handler that should be used by this stage, and
     * passes it "downstream" to any subsequent stage.
     */
    final public void setErrorHandler (ErrorHandler handler)
    {
	errHandler = handler;
	if (next != null)
	    next.setErrorHandler (handler);
    }

    /**
     * Returns the error handler assigned this filter stage, or null
     * if no such assigment has been made.
     */
    final public ErrorHandler getErrorHandler ()
    {
	return errHandler;
    }


    /**
     * Returns the next event consumer in sequence; or null if there
     * is no such handler.
     */
    final public EventConsumer getNext ()
	{ return next; }


    /**
     * Assigns the content handler to use; a null handler indicates
     * that these events will not be forwarded.
     * This overrides the previous settting for this handler, which was
     * probably pointed to the next consumer by the base class constructor.
     */
    final public void setContentHandler (ContentHandler h)
    {
	docHandler = h;
    }

    /** Returns the content handler being used. */
    final public ContentHandler getContentHandler ()
    {
	return docHandler;
    }

    /**
     * Assigns the DTD handler to use; a null handler indicates
     * that these events will not be forwarded.
     * This overrides the previous settting for this handler, which was
     * probably pointed to the next consumer by the base class constructor.
     */
    final public void setDTDHandler (DTDHandler h)
	{ dtdHandler = h; }

    /** Returns the dtd handler being used. */
    final public DTDHandler getDTDHandler ()
    {
	return dtdHandler;
    }

    /**
     * Stores the property, normally a handler; a null handler indicates
     * that these events will not be forwarded.
     * This overrides the previous handler settting, which was probably
     * pointed to the next consumer by the base class constructor.
     */
    final public void setProperty (String id, Object o)
    throws SAXNotRecognizedException, SAXNotSupportedException
    {
	try {
	    Object	value = getProperty (id);

	    if (value == o)
		return;
	    if (DECL_HANDLER.equals (id)) {
		declHandler = (DeclHandler) o;
		return;
	    }
	    if (LEXICAL_HANDLER.equals (id)) {
		lexHandler = (LexicalHandler) o;
		return;
	    }
	    throw new SAXNotSupportedException (id);

	} catch (ClassCastException e) {
	    throw new SAXNotSupportedException (id);
	}
    }

    /** Retrieves a property of unknown intent (usually a handler) */
    final public Object getProperty (String id)
    throws SAXNotRecognizedException
    {
	if (DECL_HANDLER.equals (id)) 
	    return declHandler;
	if (LEXICAL_HANDLER.equals (id))
	    return lexHandler;

	throw new SAXNotRecognizedException (id);
    }

    /**
     * Returns any locator provided to the next consumer, if this class
     * (or a subclass) is handling {@link ContentHandler } events.
     */
    public Locator getDocumentLocator ()
	{ return locator; }


    // CONTENT HANDLER DELEGATIONS

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void setDocumentLocator (Locator locator)
    {
	this.locator = locator;
	if (docNext != null)
	    docNext.setDocumentLocator (locator);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void startDocument () throws SAXException
    {
	if (docNext != null)
	    docNext.startDocument ();
    }

    public void xmlDecl(String version, String encoding, boolean standalone,
                        String inputEncoding)
      throws SAXException
    {
      if (docNext != null && docNext instanceof ContentHandler2)
        {
          ((ContentHandler2) docNext).xmlDecl(version, encoding, standalone,
                                              inputEncoding);
        }
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void skippedEntity (String name) throws SAXException
    {
	if (docNext != null)
	    docNext.skippedEntity (name);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void processingInstruction (String target, String data)
    throws SAXException
    {
	if (docNext != null)
	    docNext.processingInstruction (target, data);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void characters (char ch [], int start, int length)
    throws SAXException
    {
	if (docNext != null)
	    docNext.characters (ch, start, length);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void ignorableWhitespace (char ch [], int start, int length)
    throws SAXException
    {
	if (docNext != null)
	    docNext.ignorableWhitespace (ch, start, length);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void startPrefixMapping (String prefix, String uri)
    throws SAXException
    {
	if (docNext != null)
	    docNext.startPrefixMapping (prefix, uri);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void startElement (
	String uri, String localName,
	String qName, Attributes atts
    ) throws SAXException
    {
	if (docNext != null)
	    docNext.startElement (uri, localName, qName, atts);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void endElement (String uri, String localName, String qName)
    throws SAXException
    {
	if (docNext != null)
	    docNext.endElement (uri, localName, qName);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void endPrefixMapping (String prefix) throws SAXException
    {
	if (docNext != null)
	    docNext.endPrefixMapping (prefix);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void endDocument () throws SAXException
    {
	if (docNext != null)
	    docNext.endDocument ();
	locator = null;
    }


    // DTD HANDLER DELEGATIONS
    
    /** <b>SAX1:</b> passes this callback to the next consumer, if any */
    public void unparsedEntityDecl (
	String name,
	String publicId,
	String systemId,
	String notationName
    ) throws SAXException
    {
	if (dtdNext != null)
	    dtdNext.unparsedEntityDecl (name, publicId, systemId, notationName);
    }
    
    /** <b>SAX1:</b> passes this callback to the next consumer, if any */
    public void notationDecl (String name, String publicId, String systemId)
    throws SAXException
    {
	if (dtdNext != null)
	    dtdNext.notationDecl (name, publicId, systemId);
    }
    

    // LEXICAL HANDLER DELEGATIONS

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void startDTD (String name, String publicId, String systemId)
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.startDTD (name, publicId, systemId);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void endDTD ()
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.endDTD ();
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void comment (char ch [], int start, int length)
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.comment (ch, start, length);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void startCDATA ()
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.startCDATA ();
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void endCDATA ()
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.endCDATA ();
    }

    /**
     * <b>SAX2:</b> passes this callback to the next consumer, if any.
     */
    public void startEntity (String name)
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.startEntity (name);
    }

    /**
     * <b>SAX2:</b> passes this callback to the next consumer, if any.
     */
    public void endEntity (String name)
    throws SAXException
    {
	if (lexNext != null)
	    lexNext.endEntity (name);
    }
    

    // DECLARATION HANDLER DELEGATIONS


    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void elementDecl (String name, String model)
    throws SAXException
    {
	if (declNext != null)
	    declNext.elementDecl (name, model);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void attributeDecl (String eName, String aName,
	    String type, String mode, String value)
    throws SAXException
    {
	if (declNext != null)
	    declNext.attributeDecl (eName, aName, type, mode, value);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void externalEntityDecl (String name,
    	String publicId, String systemId)
    throws SAXException
    {
	if (declNext != null)
	    declNext.externalEntityDecl (name, publicId, systemId);
    }

    /** <b>SAX2:</b> passes this callback to the next consumer, if any */
    public void internalEntityDecl (String name, String value)
    throws SAXException
    {
	if (declNext != null)
	    declNext.internalEntityDecl (name, value);
    }
}