XMLUtil.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * 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
 */
package org.openhab.binding.rwesmarthome.internal.communicator.util;

import java.io.IOException;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

/**
 * Utility class for XML.
 *
 * @author ollie-dev
 *
 */
public class XMLUtil {

    /**
     * Returns the xml value.
     * 
     * @param sIn
     * @param sxpath
     * @return
     * @throws ParserConfigurationException
     * @throws IOException
     * @throws SAXException
     * @throws XPathExpressionException
     */
    public static String XPathValueFromString(String sIn, String sxpath)
            throws ParserConfigurationException, IOException, SAXException, XPathExpressionException {
        // DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
        Document doc = loadXMLFromString(sIn);
        XPath xPath = XPathFactory.newInstance().newXPath();
        // XPath Query for showing all nodes value
        XPathExpression expr = xPath.compile(sxpath);

        Object result = expr.evaluate(doc, XPathConstants.NODESET);
        NodeList nodes = (NodeList) result;
        String sReturn = "";
        for (int i = 0; i < nodes.getLength(); i++) {
            sReturn = nodes.item(i).getNodeValue();
        }
        return sReturn;
    }

    /**
     * Loads a string into a xml document object.
     * 
     * @param xml
     * @return
     * @throws ParserConfigurationException
     * @throws SAXException
     * @throws IOException
     */
    public static Document loadXMLFromString(String xml)
            throws ParserConfigurationException, SAXException, IOException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        InputSource is = new InputSource(new StringReader(xml));
        Document doc = builder.parse(is);
        return doc;
    }
}