namespacenode.java

Java的面向对象数据库系统的源代码

/*
 * $Header: /cvsroot/ozone/ozone/modules/xml/dom4j/src/org/jaxen/dom/NamespaceNode.java,v 1.1 2003/11/02 18:33:52 per_nyfelt Exp $
 * $Revision: 1.1 $
 * $Date: 2003/11/02 18:33:52 $
 *
 * ====================================================================
 *
 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions, and the disclaimer that follows
 *    these conditions in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. The name "Jaxen" must not be used to endorse or promote products
 *    derived from this software without prior written permission.  For
 *    written permission, please contact [e-mail].
 *
 * 4. Products derived from this software may not be called "Jaxen", nor
 *    may "Jaxen" appear in their name, without prior written permission
 *    from the Jaxen Project Management ([e-mail]).
 *
 * In addition, we request (but do not require) that you include in the
 * end-user documentation provided with the redistribution and/or in the
 * software itself an acknowledgement equivalent to the following:
 *     "This product includes software developed by the
 *      Jaxen Project (http://www.jaxen.org/)."
 * Alternatively, the acknowledgment may be graphical using the logos
 * available at http://www.jaxen.org/
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Jaxen Project and was originally
 * created by bob mcwhirter <[e-mail]> and
 * James Strachan <[e-mail]>.  For more information on the
 * Jaxen Project, please see <http://www.jaxen.org/>.
 *
 * $Id: NamespaceNode.java,v 1.1 2003/11/02 18:33:52 per_nyfelt Exp $
 */

////////////////////////////////////////////////////////////////////
// Inner class for a Namespace node.
////////////////////////////////////////////////////////////////////

package org.jaxen.dom;

import org.jaxen.pattern.Pattern;
import org.w3c.dom.*;


/**
 * Extension DOM2 node type for a Namespace Declaration.
 *
 * <p>This class implements the DOM2 {@link Node} interface to
 * allow Namespace declarations to be included in the result
 * set of an XPath selectNodes operation, even though DOM2 does
 * not model Namespace declarations as separate nodes.</p>
 *
 * <p>While all of the methods are implemented with reasonable
 * defaults, there will be some unexpected surprises, so users are
 * advised to test for NamespaceNodes and filter them out from the
 * result sets as early as possible:</p>
 *
 * <ol>
 *
 * <li>The {@link #getNodeType} method returns {@link #NAMESPACE_NODE},
 * which is not one of the usual DOM2 node types.  Generic code may
 * fall unexpectedly out of switch statements, for example.</li>
 *
 * <li>The {@link #getOwnerDocument} method returns the owner document
 * of the parent node, but that owner document will know nothing about
 * the Namespace node.</p>
 *
 * <li>The {@link #isSupported} method always returns false.</li>
 *
 * </ol>
 *
 * <p>All attempts to modify a NamespaceNode will fail with a {@link
 * DOMException} ({@link
 * DOMException#NO_MODIFICATION_ALLOWED_ERR}).</p>
 *
 * <p>This class has only protected constructors, so that it can be
 * instantiated only by {@link DocumentNavigator}.</p>
 *
 * @author David Megginson
 * @see DocumentNavigator
 */
public class NamespaceNode implements Node {


    ////////////////////////////////////////////////////////////////////
    // Constants.
    ////////////////////////////////////////////////////////////////////

    /**
     * Constant: this is a NamespaceNode.
     *
     * @see #getNodeType
     */
    public final static short NAMESPACE_NODE = Pattern.NAMESPACE_NODE;



    ////////////////////////////////////////////////////////////////////
    // Protected Constructors.
    ////////////////////////////////////////////////////////////////////


    /**
     * Constructor.
     *
     * @param parent The DOM node to which the Namespace is attached.
     * @param uri The Namespace URI as a string.
     */
    public NamespaceNode(Node parent, String name, String value) {
        this.parent = parent;
        this.name = name;
        this.value = value;
    }


    /**
     * Constructor.
     *
     * @param parent The DOM node to which the Namespace is attached.
     * @param attribute The DOM attribute object containing the
     *        Namespace declaration.
     */
    NamespaceNode(Node parent, Node attribute) {
        String name = attribute.getNodeName();

        if (name.equals("xmlns"))
            this.name = "";
        else
            this.name = name.substring(6); // the part after "xmlns:"

        this.parent = parent;
        this.value = attribute.getNodeValue();
    }



    ////////////////////////////////////////////////////////////////////
    // Implementation of org.w3c.dom.Node.
    ////////////////////////////////////////////////////////////////////


    /**
     * Get the Namespace prefix.
     *
     * @return The Namespace prefix, or "" for the default Namespace.
     */
    public String getNodeName() {
        return name;
    }


    /**
     * Get the Namespace URI.
     *
     * @return The Namespace URI.
     */
    public String getNodeValue() {
        return value;
    }


    /**
     * Change the Namespace URI (always fails).
     *
     * @param value The new URI.
     * @exception DOMException always thrown.
     */
    public void setNodeValue(String value)
            throws DOMException {
        no_mods();
    }


    /**
     * Get the node type.
     *
     * @return Always {@link #NAMESPACE_NODE}.
     */
    public short getNodeType() {
        return NAMESPACE_NODE;
    }


    /**
     * Get the parent node.
     *
     * <p>This method returns the element that was queried for Namespaces
     * in effect, <em>not</em> necessarily the actual element containing
     * the Namespace declaration.</p>
     *
     * @return The parent node (not null).
     */
    public Node getParentNode() {
        return parent;
    }


    /**
     * Get the list of child nodes.
     *
     * @return An empty node list.
     */
    public NodeList getChildNodes() {
        return new EmptyNodeList();
    }


    /**
     * Get the first child node.
     *
     * @return Always null.
     */
    public Node getFirstChild() {
        return null;
    }


    /**
     * Get the last child node.
     *
     * @return Always null.
     */
    public Node getLastChild() {
        return null;
    }


    /**
     * Get the previous sibling node.
     *
     * @return Always null.
     */
    public Node getPreviousSibling() {
        return null;
    }


    /**
     * Get the next sibling node.
     *
     * @return Always null.
     */
    public Node getNextSibling() {
        return null;
    }


    /**
     * Get the attribute nodes.
     *
     * @return Always null.
     */
    public NamedNodeMap getAttributes() {
        return null;
    }


    /**
     * Get the owner document.
     *
     * @return The owner document <em>of the parent node</em>.