Java XML Node Find findNodeByName(Document doc, String pathExpression)

Description

Searches for a node within a DOM document with a given node path expression.

License

Apache License

Parameter

Parameter	Description
doc	DOM Document to search for a node.
pathExpression	dot separated path expression

Return

Node element found in the DOM document.

Declaration

public static Node findNodeByName(Document doc, String pathExpression) 

Method Source Code

//package com.java2s;
/*//w  w  w  . j av a  2s.c o  m
 * Copyright 2006-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.util.*;

import org.w3c.dom.*;

public class Main {
    /**
     * Searches for a node within a DOM document with a given node path expression.
     * Elements are separated by '.' characters.
     * Example: Foo.Bar.Poo
     * @param doc DOM Document to search for a node.
     * @param pathExpression dot separated path expression
     * @return Node element found in the DOM document.
     */
    public static Node findNodeByName(Document doc, String pathExpression) {
        final StringTokenizer tok = new StringTokenizer(pathExpression, ".");
        final int numToks = tok.countTokens();
        NodeList elements;
        if (numToks == 1) {
            elements = doc.getElementsByTagNameNS("*", pathExpression);
            return elements.item(0);
        }

        String element = pathExpression.substring(pathExpression.lastIndexOf('.') + 1);
        elements = doc.getElementsByTagNameNS("*", element);

        String attributeName = null;
        if (elements.getLength() == 0) {
            //No element found, but maybe we are searching for an attribute
            attributeName = element;

            //cut off attributeName and set element to next token and continue
            Node found = findNodeByName(doc,
                    pathExpression.substring(0, pathExpression.length() - attributeName.length() - 1));

            if (found != null) {
                return found.getAttributes().getNamedItem(attributeName);
            } else {
                return null;
            }
        }

        StringBuffer pathName;
        Node parent;
        for (int j = 0; j < elements.getLength(); j++) {
            int cnt = numToks - 1;
            pathName = new StringBuffer(element);
            parent = elements.item(j).getParentNode();
            do {
                if (parent != null) {
                    pathName.insert(0, '.');
                    pathName.insert(0, parent.getLocalName());//getNodeName());

                    parent = parent.getParentNode();
                }
            } while (parent != null && --cnt > 0);
            if (pathName.toString().equals(pathExpression)) {
                return elements.item(j);
            }
        }

        return null;
    }
}

Related

1. findNode(Document source, Element n)
2. findNode(Node aNode, String aName)
3. findNode(Node node, String nodeName)
4. findNode(Node rootNode, String nodeName)
5. findNodeByAttribute(Document document, String tagName, String attributeName, String attributeValue)
6. findNodeByTagName(Document document, String tagName)
7. findNodeByXpath(org.w3c.dom.Document doc, String xpathEx)
8. findNodeIndex(Node node)
9. findNodeIndex(Node node)