001/**
002 *
003 * Copyright 2017-2018 Florian Schmaus.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.util;
018
019import java.io.StringReader;
020import java.io.StringWriter;
021import java.util.logging.Level;
022import java.util.logging.Logger;
023
024import javax.xml.transform.OutputKeys;
025import javax.xml.transform.Transformer;
026import javax.xml.transform.TransformerException;
027import javax.xml.transform.TransformerFactory;
028import javax.xml.transform.stream.StreamResult;
029import javax.xml.transform.stream.StreamSource;
030
031public class XmlUtil {
032
033    private static final Logger LOGGER = Logger.getLogger(XmlUtil.class.getName());
034
035    private static final TransformerFactory transformerFactory = TransformerFactory.newInstance();
036
037    static {
038        try {
039            transformerFactory.setAttribute("indent-number", 2);
040        } catch (IllegalArgumentException e) {
041            LOGGER.log(Level.INFO, "XML TransformerFactory does not support indent-number attribute", e);
042        }
043    }
044
045    public static String prettyFormatXml(CharSequence xml) {
046        String xmlString = xml.toString();
047        StreamSource source = new StreamSource(new StringReader(xmlString));
048        StringWriter stringWriter = new StringWriter();
049        StreamResult result = new StreamResult(stringWriter);
050
051        try {
052            Transformer transformer = transformerFactory.newTransformer();
053            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
054            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
055            transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
056
057            // Transform the requested string into a nice formatted XML string
058            transformer.transform(source, result);
059        }
060        catch (TransformerException | IllegalArgumentException e) {
061            LOGGER.log(Level.SEVERE, "Transformer error", e);
062            return xmlString;
063        }
064
065        return stringWriter.toString();
066    }
067
068    public static boolean isClarkNotation(String text) {
069        if (text.isEmpty()) {
070            return false;
071        }
072
073        // TODO: This is currently a mediocre heuristic to check for clark notation.
074        return text.charAt(0) == '{';
075    }
076}