Java XPath Create getXPath(Node n)

Description

Constructs a XPath query to the supplied node.

License

Open Source License

Parameter

Parameter	Description
n	a parameter

Declaration

public static String getXPath(Node n) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2015 UNIT Information Technologies R&D Ltd
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:/*from  w  w w.  j  ava  2  s  .c o m*/
 *     Ferhat Erata - initial API and implementation
 *     H. Emre Kirmizi - initial API and implementation
 *     Serhat Celik - initial API and implementation
 *     U. Anil Ozturk - initial API and implementation
 *******************************************************************************/

import java.util.Stack;

import org.w3c.dom.Element;
import org.w3c.dom.Node;

public class Main {
    /**
     * Constructs a XPath query to the supplied node.
     * 
     * {@code
     * <?xml version="1.0" encoding="iso-8859-1" ?>
     * <bookstore>
     *   <book id="1">
     *     <title>Harry Potter and the Philosopher's Stone</title>
     *     <isbn>0747532745</isbn>
     *     <tags>
     *       <tag>children</tag>
     *       <tag>stone</tag>
     *     </tags>
     *   </book>
     *   <book id="2">
     *     <title>Harry Potter and the Chamber of Secrets</title>
     *     <isbn>0747538484</isbn>
     *     <tags>
     *       <tag>children</tag>
     *       <tag>secrets</tag>
     *     </tags>
     *   </book>
     *   <book id="3">
     *     <title>Harry Potter and the Prisoner of Azkaban</title>
     *     <isbn>0747546290</isbn>
     *     <tags>
     *       <tag>children</tag>
     *       <tag>prisoner</tag>
     *     </tags>
     *   </book>
     * </bookstore>
     * }
     * 
     * Title node of "Harry Potter and the Chamber of Secrets": *
     * 
     * <pre>
     * bookstore/book[@id='2']/title[1]
     * </pre>
     * 
     * Second tag node of "Harry Potter and the Prisoner of Azkaban":
     * 
     * <pre>
     * bookstore/book[@id='3']/tags[1]/tag[2]
     * </pre>
     * 
     * @param n
     * @return
     */
    public static String getXPath(Node n) {
        // abort early
        if (null == n)
            return null;

        // declarations
        Node parent = null;
        Stack<Node> hierarchy = new Stack<Node>();
        StringBuffer buffer = new StringBuffer();

        // push element on stack
        hierarchy.push(n);

        parent = n.getParentNode();
        while (null != parent && parent.getNodeType() != Node.DOCUMENT_NODE) {
            // push on stack
            hierarchy.push(parent);

            // get parent of parent
            parent = parent.getParentNode();
        }

        // construct xpath
        Object obj = null;
        while (!hierarchy.isEmpty() && null != (obj = hierarchy.pop())) {
            Node node = (Node) obj;
            boolean handled = false;

            // only consider elements
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                Element e = (Element) node;

                // is this the root element?
                if (buffer.length() == 0) {
                    // root element - simply append element name
                    buffer.append(node.getLocalName());
                } else {
                    // child element - append slash and element name
                    buffer.append("/");
                    buffer.append(node.getLocalName());

                    if (node.hasAttributes()) {
                        // see if the element has a name or id attribute
                        if (e.hasAttribute("id")) {
                            // id attribute found - use that
                            buffer.append("[@id='" + e.getAttribute("id") + "']");
                            handled = true;
                        } else if (e.hasAttribute("name") && e.getAttribute("name") != null
                                && !e.getAttribute("name").isEmpty()) {
                            // name attribute found - use that
                            buffer.append("[@name='" + e.getAttribute("name") + "']");
                            handled = true;
                        }
                    }

                    if (!handled) {
                        // no known attribute we could use - get sibling index
                        int prev_siblings = 1;
                        Node prev_sibling = node.getPreviousSibling();
                        while (null != prev_sibling) {
                            if (prev_sibling.getNodeType() == node.getNodeType()) {
                                if (prev_sibling.getLocalName().equalsIgnoreCase(node.getLocalName())) {
                                    prev_siblings++;
                                }
                            }
                            prev_sibling = prev_sibling.getPreviousSibling();
                        }
                        buffer.append("[" + prev_siblings + "]");
                    }
                }
            }
        }

        // return buffer
        return buffer.toString();
    }
}

Related

1. getXPath()
2. getXPath()
3. getXPath(Element elt)
4. getXPath(Element rootElement, Element targetElement, boolean includeElementIndex, Map namespacesMap)
5. getXPath(NamespaceContext nsContext)
6. getXPath(Node n)
7. getXPath(Node n)
8. getXPath(Node n)
9. getXPath(Node node)