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 * Copyright 2002 - 2007 Adobe Systems Incorporated All Rights Reserved.
 * 
 * NOTICE: All information contained herein is, and remains the property of Adobe Systems Incorporated and its suppliers, if any. The intellectual and technical concepts contained herein are
 * proprietary to Adobe Systems Incorporated and its suppliers and may be covered by U.S. and Foreign Patents, patents in process, and are protected by trade secret or copyright law. Dissemination of
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package flex.messaging.util;

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

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

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

import flex.messaging.MessageException;

/**
 * Utility class for converting strings to XML documents and vice versa.
 * 
 * @exclude
 */
public class XMLUtil
{
    public static String INDENT_XML = "no";
    public static String OMIT_XML_DECLARATION = "yes";

    private XMLUtil()
    {
    }

    /**
     * Uses a TransformerFactory with an identity transformation to convert a Document into a String representation of the XML.
     * 
     * @param document
     *            Document.
     * @return An XML String.
     * @throws IOException
     *             if an error occurs during transformation.
     */
    public static String documentToString(Document document) throws IOException
    {
        String xml = null;

        try
        {
            DOMSource dom = new DOMSource(document);
            StringWriter writer = new StringWriter();
            StreamResult output = new StreamResult(writer);

            // Use Transformer to serialize a DOM
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer transformer = factory.newTransformer();

            // No need for pretty printing
            transformer.setOutputProperty(OutputKeys.INDENT, INDENT_XML);

            // XML Declarations unexpected whitespace for legacy AS XMLDocument type,
            // so we always omit it. We can't tell whether one was present when
            // constructing the Document in the first place anyway...
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, OMIT_XML_DECLARATION);

            transformer.transform(dom, output);

            xml = writer.toString();
        }
        catch (TransformerException te)
        {
            throw new IOException("Error serializing Document as String: " + te.getMessageAndLocation());
        }
        return xml;
    }

    /**
     * Uses the current DocumentBuilderFactory to converts a String representation of XML into a Document.
     * 
     * @param xml
     *            XML serialized as a String
     * @return Document
     */
    public static Document stringToDocument(String xml)
    {
        return stringToDocument(xml, true);
    }

    /**
     * Uses the current DocumentBuilderFactory to converts a String representation of XML into a Document.
     * 
     * @param xml
     *            XML serialized as a String
     * @param nameSpaceAware
     *            determines whether the constructed Document is name-space aware
     * @return Document
     */
    public static Document stringToDocument(String xml, boolean nameSpaceAware)
    {
        Document document = null;
        try
        {
            if (xml != null)
            {
                StringReader reader = new StringReader(xml);
                InputSource input = new InputSource(reader);
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                factory.setNamespaceAware(nameSpaceAware);
                factory.setValidating(false);
                DocumentBuilder builder = factory.newDocumentBuilder();

                document = builder.parse(input);
            }
        }
        catch (Exception ex)
        {
            throw new MessageException("Error deserializing XML type " + ex.getMessage());
        }

        return document;
    }
}