com.jaeksoft.searchlib.util.XmlWriter.java Source code

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Here is the source code for com.jaeksoft.searchlib.util.XmlWriter.java

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/**   
 * License Agreement for OpenSearchServer
 *
 * Copyright (C) 2008-2011 Emmanuel Keller / Jaeksoft
 * 
 * http://www.open-search-server.com
 * 
 * This file is part of OpenSearchServer.
 *
 * OpenSearchServer is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 * OpenSearchServer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with OpenSearchServer. 
 *  If not, see <http://www.gnu.org/licenses/>.
 **/

package com.jaeksoft.searchlib.util;

import java.io.PrintWriter;
import java.util.Stack;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.lang.StringEscapeUtils;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

public class XmlWriter {

    private TransformerHandler transformerHandler;

    private AttributesImpl elementAttributes;

    private Stack<String> startedElementStack;

    private Matcher controlMatcher;

    public XmlWriter(PrintWriter out, String encoding) throws TransformerConfigurationException, SAXException {
        StreamResult streamResult = new StreamResult(out);
        SAXTransformerFactory tf = (SAXTransformerFactory) SAXTransformerFactory.newInstance();
        transformerHandler = tf.newTransformerHandler();
        Transformer serializer = transformerHandler.getTransformer();
        serializer.setOutputProperty(OutputKeys.ENCODING, encoding);
        serializer.setOutputProperty(OutputKeys.INDENT, "yes");
        serializer.setOutputProperty(OutputKeys.METHOD, "xml");
        transformerHandler.setResult(streamResult);
        startedElementStack = new Stack<String>();
        transformerHandler.startDocument();
        elementAttributes = new AttributesImpl();
        Pattern p = Pattern.compile("\\p{Cntrl}");
        controlMatcher = p.matcher("");

    }

    public void textNode(Object data) throws SAXException {
        if (data == null)
            return;
        String value = data.toString();
        char[] chars = value.toCharArray();
        transformerHandler.characters(chars, 0, chars.length);
    }

    public void endDocument() throws SAXException {
        while (!startedElementStack.empty())
            endElement();
        transformerHandler.endDocument();
    }

    final public String escapeXml(String text) {
        if (text == null)
            return null;
        controlMatcher.reset(text);
        return StringEscapeUtils.escapeXml(controlMatcher.replaceAll(""));
    }

    public void startElement(String name, String... attributes) throws SAXException {
        elementAttributes.clear();
        for (int i = 0; i < attributes.length; i++) {
            String attr = attributes[i];
            String value = escapeXml(attributes[++i]);
            if (attr != null && value != null)
                elementAttributes.addAttribute("", "", attr, "CDATA", value);
        }
        startedElementStack.push(name);
        transformerHandler.startElement("", "", name, elementAttributes);

    }

    public void endElement() throws SAXException {
        transformerHandler.endElement("", "", startedElementStack.pop());
    }

    public void writeSubTextNodeIfAny(String nodeName, String content) throws SAXException {
        if (content == null)
            return;
        startElement(nodeName);
        textNode(content);
        endElement();
    }

}