namespacenode.java

XML的解析、编译、查询等技术的JAVA源代码。

/*
 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/dom/NamespaceNode.java,v 1.25 2006/07/03 11:14:05 elharo Exp $
 * $Revision: 1.25 $
 * $Date: 2006/07/03 11:14:05 $
 *
 * ====================================================================
 *
 * Copyright 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:
 * 
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 
 *   * Neither the name of the Jaxen Project nor the names of its
 *     contributors may be used to endorse or promote products derived 
 *     from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS 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 COPYRIGHT OWNER
 * OR 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 1.25 2006/07/03 11:14:05 elharo Exp $
 */

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

package org.jaxen.dom;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;

import org.jaxen.pattern.Pattern;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.UserDataHandler;


/**
 * Extension DOM2/DOM3 node type for a namespace node.
 *
 * <p>This class implements the DOM2 and DOM3 {@link Node} interface
 * to allow namespace nodes to be included in the result
 * set of an XPath selectNodes operation, even though DOM does
 * not model namespaces in scope as separate nodes.</p>
 *
 * <p>
 * While all of the DOM2 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>
 *
 * <li> The DOM3 methods sometimes throw UnsupportedOperationException.
 *      They're here only to allow this class to be compiled with Java 1.5.
 *       Do not call or rely on them.</li>
 * </ol>
 *
 * <p>All attempts to modify a <code>NamespaceNode</code> will fail with a {@link
 * DOMException} ({@link
 * DOMException#NO_MODIFICATION_ALLOWED_ERR}).</p>
 *
 * @author David Megginson
 * @author Elliotte Rusty Harold
 * @see DocumentNavigator
 */
public class NamespaceNode implements Node
{

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

    // FIXME "Note: Numeric codes up to 200 are reserved to W3C for possible future use."
    // We should be using higher codes. Here we're using 13, the same as DOM 3's type for XPathNamespace.
    // However, that's only a note not a recommendation.

    /**
     * Create a new NamespaceNode.
     *
     * @param parent the DOM node to which the namespace is attached
     * @param name the namespace prefix
     * @param value the namespace URI
     */
    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 attributeName = attribute.getNodeName();
    
        if (attributeName.equals("xmlns")) {
            this.name = "";
        }
        else if (attributeName.startsWith("xmlns:")) {
            this.name = attributeName.substring(6); // the part after "xmlns:"
        }
        else { // workaround for Crimson bug; Crimson incorrectly reports the prefix as the node name
            this.name = attributeName;
        }
        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
     * @throws DOMException always
     */
    public void setNodeValue (String value) throws DOMException
    {
        disallowModification();
    }


    /**
     * 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 null
     */
    public Node getFirstChild ()
    {
        return null;
    }


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


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


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


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


    /**
     * Get the owner document.
     *
     * @return the owner document <em>of the parent node</em>
     */
    public Document getOwnerDocument ()
    {
        if (parent == null) return null;
        return parent.getOwnerDocument();
    }


    /**
     * Insert a new child node (always fails).
     * 
     * @param newChild the node to add
     * @param refChild ignored
     * @return never
     * @throws DOMException always
     * @see Node#insertBefore
     */
    public Node insertBefore (Node newChild, Node refChild)
    throws DOMException
    {
        disallowModification();
        return null;
    }


    /**
     * Replace a child node (always fails).
     *
     * @param newChild the node to add
     * @param oldChild the child node to replace
     * @return never
     * @throws DOMException always
     * @see Node#replaceChild
     */
    public Node replaceChild (Node newChild, Node oldChild) throws DOMException
    {
        disallowModification();
        return null;
    }


    /**
     * Remove a child node (always fails).
     *
     * @param oldChild the child node to remove
     * @return never
     * @throws DOMException always
     * @see Node#removeChild
     */
    public Node removeChild(Node oldChild) throws DOMException
    {
        disallowModification();
        return null;
    }


    /**
     * Append a new child node (always fails).
     *
     * @param newChild the node to add
     * @return never
     * @throws DOMException always
     * @see Node#appendChild
     */
    public Node appendChild(Node newChild) throws DOMException
    {
        disallowModification();
        return null;
    }


    /**
     * Test for child nodes.
     *
     * @return false
     */
    public boolean hasChildNodes()
    {
        return false;
    }


    /**
     * Create a copy of this node.
     *
     * @param deep make a deep copy (no effect, since namespace nodes
     *        don't have children).
     * @return a new copy of this namespace node
     */
    public Node cloneNode (boolean deep)
    {
        return new NamespaceNode(parent, name, value);
    }


    /**
     * Normalize the text descendants of this node.
     *
     * <p>This method has no effect, since namespace nodes have no
     * descendants.</p>
     */
    public void normalize ()
    {
    // no op
    }


    /**
     * Test if a DOM2 feature is supported. (None are.)
     *
     * @param feature the feature name
     * @param version the feature version
     * @return false
     */
    public boolean isSupported(String feature, String version)
    {
        return false;
    }


    /**
     * Get the namespace URI of this node.
     *
     * <p>Namespace declarations are not themselves
     * Namespace-qualified.</p>
     *
     * @return null
     */
    public String getNamespaceURI()
    {
       return null;
    }


    /**
     * Get the namespace prefix of this node.
     *
     * <p>Namespace declarations are not themselves