nodecreaterule.java

业界著名的tomcat服务器的最新6.0的源代码。

         * @param data the processing instruction data, or null if none was 
         *   supplied
         * @throws SAXException if the DOM implementation throws an exception
         */
        public void processingInstruction(String target, String data)
            throws SAXException {
            
            try {
                top.appendChild(doc.createProcessingInstruction(target, data));
            } catch (DOMException e) {
                throw new SAXException(e.getMessage());
            }

        }


        /**
         * Adds a new child {@link org.w3c.dom.Element Element} to the current
         * node.
         * 
         * @param namespaceURI the namespace URI
         * @param localName the local name
         * @param qName the qualified (prefixed) name
         * @param atts the list of attributes
         * @throws SAXException if the DOM implementation throws an exception
         */
        public void startElement(String namespaceURI, String localName,
                                 String qName, Attributes atts)
            throws SAXException {

            try {
                Node previousTop = top;
                if ((localName == null) || (localName.length() == 0)) { 
                    top = doc.createElement(qName);
                } else {
                    top = doc.createElementNS(namespaceURI, localName);
                }
                for (int i = 0; i < atts.getLength(); i++) {
                    Attr attr = null;
                    if ((atts.getLocalName(i) == null) ||
                        (atts.getLocalName(i).length() == 0)) {
                        attr = doc.createAttribute(atts.getQName(i));
                        attr.setNodeValue(atts.getValue(i));
                        ((Element)top).setAttributeNode(attr);
                    } else {
                        attr = doc.createAttributeNS(atts.getURI(i),
                                                     atts.getLocalName(i));
                        attr.setNodeValue(atts.getValue(i));
                        ((Element)top).setAttributeNodeNS(attr);
                    }
                }
                previousTop.appendChild(top);
                depth++;
            } catch (DOMException e) {
                throw new SAXException(e.getMessage());
            }

        }

    }


    // ----------------------------------------------------------- Constructors


    /**
     * Default constructor. Creates an instance of this rule that will create a
     * DOM {@link org.w3c.dom.Element Element}.
     */
    public NodeCreateRule() throws ParserConfigurationException {

        this(Node.ELEMENT_NODE);

    }


    /**
     * Constructor. Creates an instance of this rule that will create a DOM
     * {@link org.w3c.dom.Element Element}, but lets you specify the JAXP 
     * <code>DocumentBuilder</code> that should be used when constructing the
     * node tree.
     * 
     * @param documentBuilder the JAXP <code>DocumentBuilder</code> to use
     */
    public NodeCreateRule(DocumentBuilder documentBuilder) {

        this(Node.ELEMENT_NODE, documentBuilder);

    }


    /**
     * Constructor. Creates an instance of this rule that will create either a 
     * DOM {@link org.w3c.dom.Element Element} or a DOM 
     * {@link org.w3c.dom.DocumentFragment DocumentFragment}, depending on the
     * value of the <code>nodeType</code> parameter.
     * 
     * @param nodeType the type of node to create, which can be either
     *   {@link org.w3c.dom.Node#ELEMENT_NODE Node.ELEMENT_NODE} or 
     *   {@link org.w3c.dom.Node#DOCUMENT_FRAGMENT_NODE Node.DOCUMENT_FRAGMENT_NODE}
     * @throws IllegalArgumentException if the node type is not supported
     */
    public NodeCreateRule(int nodeType) throws ParserConfigurationException {

        this(nodeType,
             DocumentBuilderFactory.newInstance().newDocumentBuilder());

    }


    /**
     * Constructor. Creates an instance of this rule that will create either a 
     * DOM {@link org.w3c.dom.Element Element} or a DOM 
     * {@link org.w3c.dom.DocumentFragment DocumentFragment}, depending on the
     * value of the <code>nodeType</code> parameter. This constructor lets you
     * specify the JAXP <code>DocumentBuilder</code> that should be used when
     * constructing the node tree.
     * 
     * @param nodeType the type of node to create, which can be either
     *   {@link org.w3c.dom.Node#ELEMENT_NODE Node.ELEMENT_NODE} or 
     *   {@link org.w3c.dom.Node#DOCUMENT_FRAGMENT_NODE Node.DOCUMENT_FRAGMENT_NODE}
     * @param documentBuilder the JAXP <code>DocumentBuilder</code> to use
     * @throws IllegalArgumentException if the node type is not supported
     */
    public NodeCreateRule(int nodeType, DocumentBuilder documentBuilder) {

        if (!((nodeType == Node.DOCUMENT_FRAGMENT_NODE) ||
              (nodeType == Node.ELEMENT_NODE))) {
            throw new IllegalArgumentException(
                "Can only create nodes of type DocumentFragment and Element");
        }
        this.nodeType = nodeType;
        this.documentBuilder = documentBuilder;

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The JAXP <code>DocumentBuilder</code> to use.
     */
    private DocumentBuilder documentBuilder = null;


    /**
     * The type of the node that should be created. Must be one of the
     * constants defined in {@link org.w3c.dom.Node Node}, but currently only
     * {@link org.w3c.dom.Node#ELEMENT_NODE Node.ELEMENT_NODE} and 
     * {@link org.w3c.dom.Node#DOCUMENT_FRAGMENT_NODE Node.DOCUMENT_FRAGMENT_NODE}
     * are allowed values.
     */
    private int nodeType = Node.ELEMENT_NODE;


    // ----------------------------------------------------------- Rule Methods


    /**
     * Implemented to replace the content handler currently in use by a 
     * NodeBuilder.
     * 
     * @param namespaceURI the namespace URI of the matching element, or an 
     *   empty string if the parser is not namespace aware or the element has
     *   no namespace
     * @param name the local name if the parser is namespace aware, or just 
     *   the element name otherwise
     * @param attributes The attribute list of this element
     * @throws Exception indicates a JAXP configuration problem
     */
    public void begin(String namespaceURI, String name, Attributes attributes)
        throws Exception {

        XMLReader xmlReader = getDigester().getXMLReader();
        Document doc = documentBuilder.newDocument();
        NodeBuilder builder = null;
        if (nodeType == Node.ELEMENT_NODE) {
            Element element = null;
            if (getDigester().getNamespaceAware()) {
                element =
                    doc.createElementNS(namespaceURI, name);
                for (int i = 0; i < attributes.getLength(); i++) {
                    element.setAttributeNS(attributes.getURI(i),
                                           attributes.getLocalName(i),
                                           attributes.getValue(i));
                }
            } else {
                element = doc.createElement(name);
                for (int i = 0; i < attributes.getLength(); i++) {
                    element.setAttribute(attributes.getQName(i),
                                         attributes.getValue(i));
                }
            }
            builder = new NodeBuilder(doc, element);
        } else {
            builder = new NodeBuilder(doc, doc.createDocumentFragment());
        }
        xmlReader.setContentHandler(builder);

    }


    /**
     * Pop the Node off the top of the stack.
     */
    public void end() throws Exception {

        Object top = digester.pop();

    }


}