ca.nines.ise.util.XMLDriver.java Source code

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Here is the source code for ca.nines.ise.util.XMLDriver.java

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/*
 * Copyright (C) 2014 Michael Joyce <ubermichael@gmail.com>
 *
 * This program 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 version 2.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package ca.nines.ise.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.commons.io.IOUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;

/**
 * XMLDriver provides XML parsing for strings, files, and input streams. The
 * documents and nodes returned from XMLDriver include location information
 * about where the document or node came from.
 *
 * @author Michael Joyce <ubermichael@gmail.com>
 */
public class XMLDriver {

    /**
     * docBuilder constructs an empty document.
     */
    private final DocumentBuilder docBuilder;

    /**
     * nullTransformer serializes an XML DOM into a string.
     */
    private final Transformer nullTransformer;

    /**
     * xmlReader consumes XML.
     */
    private final XMLReader xmlReader;

    /**
     * Construct a driver.
     *
     * @throws ParserConfigurationException
     * @throws TransformerConfigurationException
     * @throws SAXException
     * @throws TransformerException
     */
    public XMLDriver() throws ParserConfigurationException, TransformerConfigurationException, SAXException,
            TransformerException {
        docBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        nullTransformer = TransformerFactory.newInstance().newTransformer();

        SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
        saxParserFactory.setNamespaceAware(true);
        SAXParser saxParser = saxParserFactory.newSAXParser();

        xmlReader = saxParser.getXMLReader();
    }

    /**
     * Parse the file and add location information to the document and each node
     * in the document.
     *
     * @param in
     * @return Document
     * @throws TransformerException
     * @throws IOException
     */
    public Document drive(File in) throws TransformerException, IOException {
        Document doc = docBuilder.newDocument();
        DOMResult domResult = new DOMResult(doc);
        LocationAnnotator locationAnnotator = new LocationAnnotator(xmlReader, doc);

        String systemId = in.getCanonicalPath();
        InputSource inputSource = new InputSource(systemId);
        SAXSource saxSource = new SAXSource(locationAnnotator, inputSource);
        nullTransformer.transform(saxSource, domResult);

        return doc;
    }

    /**
     * Parse an input stream and add location information to the document and the
     * nodes in the document. {@code source} is the source of the XML. Useful for
     * reading XML documents inside the bundled up JAR.
     *
     * <pre><code>
     * String loc = "/resources/schemas/default.xml";
     * InputStream in = Schema.class.getResourceAsStream(loc);
     * XMLDriver driver = new XMLDriver();
     * Document doc = driver.drive(in);
     * </code></pre>
     *
     * @param source the source of the XML
     * @param in the input stream
     * @return a W3C document
     *
     * @throws TransformerException
     * @throws IOException
     */
    public Document drive(String source, InputStream in) throws TransformerException, IOException {
        Document doc = docBuilder.newDocument();
        DOMResult domResult = new DOMResult(doc);
        LocationAnnotator locationAnnotator = new LocationAnnotator(source, xmlReader, doc);

        InputSource inputSource = new InputSource(in);
        SAXSource saxSource = new SAXSource(locationAnnotator, inputSource);
        nullTransformer.transform(saxSource, domResult);

        return doc;
    }

    /**
     * Parse a string for XML. Mostly useful for testing.
     *
     * @param in
     * @return Document
     * @throws TransformerException
     */
    public Document drive(String in) throws TransformerException {
        Document doc = docBuilder.newDocument();
        DOMResult domResult = new DOMResult(doc);
        LocationAnnotator locationAnnotator = new LocationAnnotator(xmlReader, doc);

        InputSource inputSource = new InputSource(IOUtils.toInputStream(in));
        SAXSource saxSource = new SAXSource(locationAnnotator, inputSource);
        nullTransformer.transform(saxSource, domResult);

        return doc;
    }

    /**
     * Serialize an Element into a string containing XML.
     *
     * @param element
     * @return String
     * @throws TransformerConfigurationException
     * @throws TransformerException
     * @throws UnsupportedEncodingException
     */
    public String serialize(Element element)
            throws TransformerConfigurationException, TransformerException, UnsupportedEncodingException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();

        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.INDENT, "no");
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        DOMSource source = new DOMSource(element);
        StreamResult stream = new StreamResult(out);
        transformer.transform(source, stream);
        return new String(out.toByteArray(), "UTF-8");
    }
}