1 files changed, 284 insertions, 0 deletions
diff --git a/src/main/java/org/openslx/libvirt/xml/LibvirtXmlSchemaValidator.java b/src/main/java/org/openslx/libvirt/xml/LibvirtXmlSchemaValidator.java
new file mode 100644
index 0000000..d589d41
--- /dev/null
+++ b/src/main/java/org/openslx/libvirt/xml/LibvirtXmlSchemaValidator.java
@@ -0,0 +1,284 @@
+package org.openslx.libvirt.xml;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+
+import javax.xml.XMLConstants;
+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 javax.xml.transform.stream.StreamSource;
+import javax.xml.validation.Schema;
+import javax.xml.validation.SchemaFactory;
+import javax.xml.validation.Validator;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.ls.LSInput;
+import org.w3c.dom.ls.LSResourceResolver;
+import org.xml.sax.SAXException;
+
+/**
+ * Resource resolver input for RelaxNG schemas.
+ * 
+ * @author Manuel Bentele
+ * @version 1.0
+ */
+class LibvirtXmlSchemaResourceInput implements LSInput
+{
+	/**
+	 * Stores the public identification of the schema resource.
+	 */
+	private String publicId;
+
+	/**
+	 * Stores the system identification of the schema resource.
+	 */
+	private String systemId;
+
+	/**
+	 * Stream to process and read the schema resource.
+	 */
+	private BufferedInputStream inputStream;
+
+	/**
+	 * Creates a resource resolver input for a RelaxNG schema.
+	 * 
+	 * @param publicId public identification of the schema resource.
+	 * @param sysId system identification of the schema resource.
+	 * @param input stream of the schema resource.
+	 */
+	public LibvirtXmlSchemaResourceInput( String publicId, String sysId, InputStream input )
+	{
+		this.publicId = publicId;
+		this.systemId = sysId;
+		this.inputStream = new BufferedInputStream( input );
+	}
+
+	@Override
+	public String getBaseURI()
+	{
+		return null;
+	}
+
+	@Override
+	public InputStream getByteStream()
+	{
+		return null;
+	}
+
+	@Override
+	public boolean getCertifiedText()
+	{
+		return false;
+	}
+
+	@Override
+	public Reader getCharacterStream()
+	{
+		return null;
+	}
+
+	@Override
+	public String getEncoding()
+	{
+		return null;
+	}
+
+	@Override
+	public String getPublicId()
+	{
+		return this.publicId;
+	}
+
+	@Override
+	public String getStringData()
+	{
+		String data = null;
+
+		synchronized ( this.inputStream ) {
+			try {
+				int inputLength = this.inputStream.available();
+				byte[] input = new byte[ inputLength ];
+				this.inputStream.read( input );
+				data = new String( input, StandardCharsets.UTF_8 );
+			} catch ( IOException e ) {
+				e.printStackTrace();
+			}
+		}
+
+		return data;
+	}
+
+	@Override
+	public String getSystemId()
+	{
+		return this.systemId;
+	}
+
+	@Override
+	public void setBaseURI( String arg0 )
+	{
+	}
+
+	@Override
+	public void setByteStream( InputStream arg0 )
+	{
+	}
+
+	@Override
+	public void setCertifiedText( boolean arg0 )
+	{
+	}
+
+	@Override
+	public void setCharacterStream( Reader arg0 )
+	{
+	}
+
+	@Override
+	public void setEncoding( String arg0 )
+	{
+	}
+
+	@Override
+	public void setPublicId( String arg0 )
+	{
+		this.publicId = arg0;
+	}
+
+	@Override
+	public void setStringData( String arg0 )
+	{
+	}
+
+	@Override
+	public void setSystemId( String arg0 )
+	{
+		this.systemId = arg0;
+	}
+}
+
+/**
+ * Resource resolver for RelaxNG schemas.
+ * 
+ * @author Manuel Bentele
+ * @version 1.0
+ */
+class LibvirtXmlSchemaResourceResolver implements LSResourceResolver
+{
+	@Override
+	public LSInput resolveResource( String type, String namespaceURI, String publicId, String systemId, String baseURI )
+	{
+		InputStream rngResourceStream = LibvirtXmlResources.getLibvirtRng( systemId );
+		return new LibvirtXmlSchemaResourceInput( publicId, systemId, rngResourceStream );
+	}
+}
+
+/**
+ * Validator for validation of Libvirt XML documents with RelaxNG schemas.
+ * 
+ * @author Manuel Bentele
+ * @version 1.0
+ */
+public class LibvirtXmlSchemaValidator
+{
+	/**
+	 * RelaxNG based validator for validation of Libvirt XML documents.
+	 */
+	private Validator rngSchemaValidator;
+
+	/**
+	 * Creates a validator for validation of Libvirt XML documents with RelaxNG schemas.
+	 * 
+	 * @param rngSchema RelaxNG schema used for validation with {@link #validate(Document)}.
+	 * 
+	 * @throws SAXException creation of a Libvirt XML validator failed.
+	 */
+	public LibvirtXmlSchemaValidator( InputStream rngSchema ) throws SAXException
+	{
+		this.createValidationContext( rngSchema );
+	}
+
+	/**
+	 * Creates context for validation of Libvirt XML documents with a RelaxNG schema.
+	 * 
+	 * @param rngSchema RelaxNG schema used for validation with {@link #validate(Document)}.
+	 * 
+	 * @throws SAXException Loading, creation and processing of <code>rngSchema</code> has failed.
+	 */
+	private void createValidationContext( InputStream rngSchema ) throws SAXException
+	{
+		// use hack to load specific schema factory implementation for RelaxNG schemas
+		System.setProperty( SchemaFactory.class.getName() + ":" + XMLConstants.RELAXNG_NS_URI,
+				"com.thaiopensource.relaxng.jaxp.XMLSyntaxSchemaFactory" );
+
+		// create schema resource resolver to resolve schema resources during parsing and validation
+		LibvirtXmlSchemaResourceResolver schemaResolver = new LibvirtXmlSchemaResourceResolver();
+
+		// create schema factory to be able to create a RelaxNG schema validator
+		SchemaFactory factory = SchemaFactory.newInstance( XMLConstants.RELAXNG_NS_URI );
+		factory.setResourceResolver( schemaResolver );
+		Schema schema = factory.newSchema( new StreamSource( rngSchema ) );
+
+		// create the RelaxNG schema validator
+		this.rngSchemaValidator = schema.newValidator();
+		this.rngSchemaValidator.setResourceResolver( schemaResolver );
+	}
+
+	/**
+	 * Transforms a DOM source to a Stream source.
+	 * 
+	 * @param domSource DOM source of a Libvirt XML document.
+	 * @return Stream source of a Libvirt XML document.
+	 * 
+	 * @throws TransformerException Transformation of DOM source to a Stream source has failed.
+	 * 
+	 * @implNote This utility method is necessary in {@link #validate(Document)} to be able to
+	 *           validate a DOM Libvirt XML document with the schema and validator implementation for
+	 *           RelaxNG schema files from
+	 *           <code>com.thaiopensource.relaxng.jaxp.XMLSyntaxSchemaFactory</code>.
+	 */
+	private static StreamSource toStreamSource( DOMSource domSource ) throws TransformerException
+	{
+		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+		StreamResult result = new StreamResult( outputStream );
+
+		// create identity transformer
+		Transformer transformer = TransformerFactory.newInstance().newTransformer();
+		transformer.transform( domSource, result );
+
+		ByteArrayInputStream inputStream = new ByteArrayInputStream( outputStream.toByteArray() );
+		return new StreamSource( inputStream );
+	}
+
+	/**
+	 * Validates a given (and parsed) DOM Libvirt XML document.
+	 * 
+	 * Validation takes place if the specified <code>xmlDocument</code> is non-null, otherwise the
+	 * validation succeeds immediately. If the validation of the <code>xmlDocument</code> fails, a
+	 * validation exception is thrown.
+	 * 
+	 * @param xmlDocument Libvirt XML document.
+	 * 
+	 * @throws LibvirtXmlValidationException Validation of Libvirt XML document failed.
+	 */
+	public void validate( Document xmlDocument ) throws LibvirtXmlValidationException
+	{
+		if ( xmlDocument != null ) {
+			try {
+				DOMSource domSource = new DOMSource( xmlDocument );
+				StreamSource source = LibvirtXmlSchemaValidator.toStreamSource( domSource );
+				this.rngSchemaValidator.validate( source );
+			} catch ( SAXException | TransformerException | IOException e ) {
+				throw new LibvirtXmlValidationException( e.getLocalizedMessage() );
+			}
+		}
+	}
+}