Java XPath Create getXPath(Node n)

Description

Constructs a XPath query to the supplied node.

License

Apache License

Parameter

Parameter	Description
n	a parameter

Declaration

public static String getXPath(Node n) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.util.Stack;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

public class Main {
    /**//from  w w  w. jav a  2 s. c  o m
     * Constructs a XPath query to the supplied node.
     *
     * @param n
     * @return
     */
    public static String getXPath(Node n) {
        // abort early
        if (null == n)
            return null;

        // declarations
        Node parent = null;
        Stack hierarchy = new Stack();
        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")) {
                            // 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(Element rootElement, Element targetElement, boolean includeElementIndex, Map namespacesMap)
2. getXPath(NamespaceContext nsContext)
3. getXPath(Node n)
4. getXPath(Node n)
5. getXPath(Node n)
6. getXPath(Node node)
7. getXPath(Node node)
8. getXPath(Node node)
9. getXPath(Node node, String xpath)