defaultnamespacecontext.java

Java的面向对象数据库系统的源代码

/*
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 *
 * $Id: DefaultNamespaceContext.java,v 1.3 2003/11/02 18:05:00 per_nyfelt Exp $
 */

package org.dom4j.xpath;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Namespace;
import org.dom4j.Node;
import org.jaxen.NamespaceContext;

import java.io.Serializable;


/** <p><code>DefaultNamespaceContext</code> implements a Jaxen
  * NamespaceContext such that a context node is used
  * to determine the current XPath namespace prefixes and namespace URIs
  * available.</p>
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  */
public class DefaultNamespaceContext implements NamespaceContext, Serializable {

    private final Element element;

    public DefaultNamespaceContext(Element element) {
        this.element = element;
    }

    public static DefaultNamespaceContext create(Object node) {
        Element element = null;
        if ( node instanceof Element ) {
            element = (Element) node;
        }
        else if ( node instanceof Document ) {
            Document doc = (Document) node;
            element = doc.getRootElement();
        }
        else if ( node instanceof Node ) {
            element = ((Node) node).getParent();
        }
        if (element != null) {
            return new DefaultNamespaceContext(element);
        }
        return null;
    }

    public String translateNamespacePrefixToUri(String prefix) {
        if ( prefix != null && prefix.length() > 0 ) {
            Namespace ns = element.getNamespaceForPrefix( prefix );
            if ( ns != null ) {
                return ns.getURI();
            }
        }
        return null;
    }
}




/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 2. 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.
 *
 * 3. The name "DOM4J" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of MetaStuff, Ltd.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "DOM4J"
 *    nor may "DOM4J" appear in their names without prior written
 *    permission of MetaStuff, Ltd. DOM4J is a registered
 *    trademark of MetaStuff, Ltd.
 *
 * 5. Due credit should be given to the DOM4J Project
 *    (http://dom4j.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS
 * ``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
 * METASTUFF, LTD. OR ITS 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.
 *
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * $Id: DefaultNamespaceContext.java,v 1.3 2003/11/02 18:05:00 per_nyfelt Exp $
 */