nl.ellipsis.webdav.server.util.XMLHelper.java Source code

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Here is the source code for nl.ellipsis.webdav.server.util.XMLHelper.java

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/*
 * Copyright 2018 Ellipsis BV, The Netherlands
 * 
 * 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.
 */
package nl.ellipsis.webdav.server.util;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.Vector;

import javax.servlet.ServletException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.io.IOUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class XMLHelper {

    private static DocumentBuilder documentBuilder;

    /**
     * Return JAXP document builder instance.
     * @throws ParserConfigurationException 
     */
    public static DocumentBuilder getDocumentBuilder() throws ServletException, ParserConfigurationException {
        if (documentBuilder == null) {
            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
            documentBuilderFactory.setNamespaceAware(true);
            documentBuilder = documentBuilderFactory.newDocumentBuilder();
        }
        return documentBuilder;
    }

    public static Node findSubElement(Node parent, String localName) {
        if (parent == null) {
            return null;
        }
        Node child = parent.getFirstChild();
        while (child != null) {
            if ((child.getNodeType() == Node.ELEMENT_NODE) && (child.getLocalName().equals(localName))) {
                return child;
            }
            child = child.getNextSibling();
        }
        return null;
    }

    public static String format(String xml) {
        String retval = xml;

        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        Document document = null;
        StringReader sr = null;
        try {
            sr = new StringReader(xml);
            InputSource inputSource = new InputSource(sr);
            documentBuilderFactory.setNamespaceAware(true);
            document = documentBuilderFactory.newDocumentBuilder().parse(inputSource);
        } catch (SAXException | IOException | ParserConfigurationException e) {
            e.printStackTrace();
        } finally {
            sr.close();
        }
        if (document != null) {
            retval = format(document);
        }
        return retval;
    }

    public static String format(Document document) {
        String retval = null;
        if (document != null) {
            TransformerFactory transfac = TransformerFactory.newInstance();
            StringWriter sw = null;
            try {
                Transformer transformer = transfac.newTransformer();

                transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
                transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
                transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
                transformer.setOutputProperty(OutputKeys.INDENT, "yes");

                //create string from xml tree
                sw = new StringWriter();
                StreamResult result = new StreamResult(sw);

                DOMSource source = new DOMSource(document);

                transformer.transform(source, result);

                retval = sw.toString();
            } catch (TransformerException e) {
                e.printStackTrace();
            } finally {
                try {
                    sw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return retval;
    }

    public static Vector<String> getPropertiesFromXML(Node propNode) {
        Vector<String> properties;
        properties = new Vector<String>();
        NodeList childList = propNode.getChildNodes();

        for (int i = 0; i < childList.getLength(); i++) {
            Node currentNode = childList.item(i);
            if (currentNode.getNodeType() == Node.ELEMENT_NODE) {
                String nodeName = currentNode.getLocalName();
                String namespace = currentNode.getNamespaceURI();
                String propertyName = null;
                if (nodeName.indexOf(':') != -1) {
                    propertyName = nodeName.substring(nodeName.indexOf(':') + 1);
                } else {
                    propertyName = nodeName;
                }
                // href is a live property which is handled differently
                properties.addElement(propertyName);
            }
        }
        return properties;
    }

}