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package org.openslx.libvirt.xml;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
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.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import org.openslx.util.XmlHelper;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* A generic representation of a Libvirt XML file.
*
* @implNote Base class to derive the representation of specific Libvirt XML files.
*
* @author Manuel Bentele
* @version 1.0
*/
public abstract class LibvirtXmlDocument implements LibvirtXmlSerializable, LibvirtXmlValidatable
{
/**
* Document builder to parse Libvirt XML document from file.
*/
private DocumentBuilder domBuilder = null;
/**
* Representation of a Libvirt XML document.
*/
private Document xmlDocument = null;
/**
* XML transformer to transform Libvirt XML document to a file.
*/
private Transformer xmlTransformer = null;
/**
* XML root node of the Libvirt XML document.
*/
private LibvirtXmlNode rootXmlNode = null;
/**
* RNG schema validator to validate the Libvirt XML document content.
*/
private LibvirtXmlSchemaValidator rngValidator = null;
/**
* Creates and initializes XML context to create and transform a Libvirt XML file from/to a file.
*
* @param rngSchema RNG schema to validate the Libvirt XML document content.
*
* @throws LibvirtXmlDocumentException error occured during setup of the XML context to read and
* write from/to a Libvirt XML file.
*/
private void createXmlContext( InputStream rngSchema ) throws LibvirtXmlDocumentException
{
// used for XML input
try {
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setIgnoringElementContentWhitespace( true );
domFactory.setNamespaceAware( true );
this.domBuilder = domFactory.newDocumentBuilder();
} catch ( ParserConfigurationException e ) {
String errorMsg = "Setting up XML context for reading from the Libvirt XML document failed.";
throw new LibvirtXmlDocumentException( errorMsg );
}
// used for XML output
try {
// use hack to load specific transformer factory implementation for XSLT
System.setProperty( TransformerFactory.class.getName(),
"org.apache.xalan.processor.TransformerFactoryImpl" );
// create XML transformer factory to create XML transformer with specific indentation
TransformerFactory transformerFactory = TransformerFactory.newInstance();
// create XML transformer and apply settings for output XML transformation
InputStream xslOutputSchemaStream = LibvirtXmlResources.getLibvirtXsl( "xml-output-transformation.xsl" );
StreamSource xslOutputSchema = new StreamSource( xslOutputSchemaStream );
this.xmlTransformer = transformerFactory.newTransformer( xslOutputSchema );
this.xmlTransformer.setOutputProperty( OutputKeys.ENCODING, "UTF-8" );
} catch ( TransformerConfigurationException e ) {
String errorMsg = "Setting up XML context for writing to the Libvirt XML document failed.";
throw new LibvirtXmlDocumentException( errorMsg );
}
// used for XML validation with RNG schema files
if ( rngSchema != null ) {
try {
this.rngValidator = new LibvirtXmlSchemaValidator( rngSchema );
} catch ( SAXException e ) {
String errorMsg = "Setting up XML context for validating to the Libvirt XML document failed.";
e.printStackTrace();
throw new LibvirtXmlDocumentException( errorMsg );
}
}
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link String}.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( String xml )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this( xml, null );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link String}.
* @param rngSchema RNG schema to validate XML content.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( String xml, InputStream rngSchema )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this.createXmlContext( rngSchema );
this.fromXml( xml );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link File}.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( File xml )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this( xml, null );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link File}.
* @param rngSchema RNG schema to validate XML content.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( File xml, InputStream rngSchema )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this.createXmlContext( rngSchema );
this.fromXml( xml );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link InputStream}.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( InputStream xml )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this( xml, null );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link InputStream}.
* @param rngSchema RNG schema to validate XML content.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( InputStream xml, InputStream rngSchema )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this.createXmlContext( rngSchema );
this.fromXml( xml );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link InputSource}.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( InputSource xml )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this( xml, null );
}
/**
* Creates a Libvirt XML document from a given XML content.
*
* @param xml XML content as {@link InputSource}.
* @param rngSchema RNG schema to validate XML content.
*
* @throws LibvirtXmlDocumentException creation of XML context failed.
* @throws LibvirtXmlSerializationException serialization of the XML content failed.
*/
public LibvirtXmlDocument( InputSource xml, InputStream rngSchema )
throws LibvirtXmlDocumentException, LibvirtXmlSerializationException
{
this.createXmlContext( rngSchema );
this.fromXml( xml );
}
/**
* Returns the XML root node of the Libvirt XML document.
*
* @return root node of the Libvirt XML document.
*/
public LibvirtXmlNode getRootXmlNode()
{
return this.rootXmlNode;
}
@Override
public void fromXml( String xml ) throws LibvirtXmlSerializationException
{
this.fromXml( new InputSource( new StringReader( xml ) ) );
}
@Override
public void fromXml( File xml ) throws LibvirtXmlSerializationException
{
try {
this.xmlDocument = this.domBuilder.parse( xml );
this.xmlDocument.getDocumentElement().normalize();
} catch ( SAXException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
} catch ( IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
}
this.rootXmlNode = new LibvirtXmlNode( this.xmlDocument, this.xmlDocument.getDocumentElement() );
}
@Override
public void fromXml( InputStream xml ) throws LibvirtXmlSerializationException
{
try {
this.xmlDocument = this.domBuilder.parse( xml );
this.xmlDocument.getDocumentElement().normalize();
} catch ( SAXException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
} catch ( IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
}
this.rootXmlNode = new LibvirtXmlNode( this.xmlDocument, this.xmlDocument.getDocumentElement() );
}
@Override
public void fromXml( InputSource xml ) throws LibvirtXmlSerializationException
{
try {
this.xmlDocument = this.domBuilder.parse( xml );
this.xmlDocument.getDocumentElement().normalize();
} catch ( SAXException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
} catch ( IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
}
this.rootXmlNode = new LibvirtXmlNode( this.xmlDocument, this.xmlDocument.getDocumentElement() );
}
@Override
public String toXml() throws LibvirtXmlSerializationException
{
StringWriter xmlWriter = null;
String xml = null;
try {
xmlWriter = new StringWriter();
DOMSource source = new DOMSource( this.xmlDocument );
StreamResult xmlString = new StreamResult( xmlWriter );
this.xmlTransformer.transform( source, xmlString );
xml = xmlWriter.toString();
xmlWriter.close();
} catch ( TransformerException | IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
} finally {
try {
xmlWriter.close();
} catch ( IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
}
}
return xml;
}
@Override
public void toXml( File xml ) throws LibvirtXmlSerializationException
{
FileWriter xmlWriter = null;
try {
xmlWriter = new FileWriter( xml );
DOMSource source = new DOMSource( this.xmlDocument );
StreamResult xmlStream = new StreamResult( xmlWriter );
this.xmlTransformer.transform( source, xmlStream );
xmlWriter.close();
} catch ( TransformerException | IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
} finally {
try {
xmlWriter.close();
} catch ( IOException e ) {
throw new LibvirtXmlSerializationException( e.getLocalizedMessage() );
}
}
}
@Override
public void validateXml() throws LibvirtXmlValidationException
{
if ( this.rngValidator != null ) {
this.rngValidator.validate( this.xmlDocument );
}
}
@Override
public String toString()
{
try {
return this.toXml();
} catch ( LibvirtXmlSerializationException e ) {
return null;
}
}
}
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