1 files changed, 350 insertions, 0 deletions
diff --git a/src/main/java/org/openslx/libvirt/xml/LibvirtXmlNode.java b/src/main/java/org/openslx/libvirt/xml/LibvirtXmlNode.java
new file mode 100644
index 0000000..a941acb
--- /dev/null
+++ b/src/main/java/org/openslx/libvirt/xml/LibvirtXmlNode.java
@@ -0,0 +1,350 @@
+package org.openslx.libvirt.xml;
+
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * A representation of a XML node as part of a {@link LibvirtXmlDocument}.
+ * 
+ * @author Manuel Bentele
+ * @version 1.0
+ */
+public class LibvirtXmlNode implements LibvirtXmlCreatable, LibvirtXmlEditable
+{
+	/**
+	 * Separation character for internal XPath expressions.
+	 */
+	private static final String XPATH_EXPRESSION_SEPARATOR = "/";
+
+	/**
+	 * Current XML node selection character for internal XPath expressions.
+	 */
+	private static final String XPATH_EXPRESSION_CURRENT_NODE = ".";
+
+	/**
+	 * Factory to create XPath objects.
+	 */
+	private XPathFactory xPathFactory = null;
+
+	/**
+	 * Representation of the XML document, in which this {@link LibvirtXmlNode} is part of.
+	 */
+	private Document xmlDocument = null;
+
+	/**
+	 * Current XML base node as XML root anchor for relative internal XPath expressions.
+	 */
+	private Node xmlBaseNode = null;
+
+	/**
+	 * Create and initialize XPath context to define and compile custom XPath expressions.
+	 */
+	private void createXPathContext()
+	{
+		this.xPathFactory = XPathFactory.newInstance();
+	}
+
+	/**
+	 * Creates empty Libvirt XML node, which does not belong to any XML document and does not specify
+	 * any XML base node.
+	 * 
+	 * @implNote Please call {@link LibvirtXmlNode#setXmlDocument(Document)} and
+	 *           {@link LibvirtXmlNode#setXmlBaseNode(Node)} manually to obtain a functional Libvirt
+	 *           XML node.
+	 */
+	public LibvirtXmlNode()
+	{
+		this( null, null );
+	}
+
+	/**
+	 * Creates Libvirt XML node from a existing Libvirt XML node by reference.
+	 * 
+	 * @param xmlNode existing Libvirt XML node.
+	 */
+	public LibvirtXmlNode( LibvirtXmlNode xmlNode )
+	{
+		this( xmlNode.getXmlDocument(), xmlNode.getXmlBaseNode() );
+	}
+
+	/**
+	 * Creates Libvirt XML node as part of a existing XML document.
+	 * 
+	 * @param xmlDocument existing XML document.
+	 * 
+	 * @implNote Please call {@link LibvirtXmlNode#setXmlBaseNode(Node)} manually to obtain a
+	 *           functional Libvirt XML node.
+	 */
+	public LibvirtXmlNode( Document xmlDocument )
+	{
+		this( xmlDocument, null );
+	}
+
+	/**
+	 * Creates Libvirt XML node with a specific XML base node.
+	 * 
+	 * @param xmlBaseNode existing XML base node.
+	 * 
+	 * @implNote Please call {@link LibvirtXmlNode#setXmlDocument(Document)} manually to obtain a
+	 *           functional Libvirt XML node.
+	 */
+	public LibvirtXmlNode( Node xmlBaseNode )
+	{
+		this( null, xmlBaseNode );
+	}
+
+	/**
+	 * Creates Libvirt XML node with a specific XML base node as part of a XML document.
+	 * 
+	 * @param xmlDocument existing XML document.
+	 * @param xmlBaseNode existing XML base node.
+	 */
+	public LibvirtXmlNode( Document xmlDocument, Node xmlBaseNode )
+	{
+		this.createXPathContext();
+
+		this.setXmlDocument( xmlDocument );
+		this.setXmlBaseNode( xmlBaseNode );
+	}
+
+	/**
+	 * Returns referenced XML document.
+	 * 
+	 * @return referenced XML document.
+	 */
+	public Document getXmlDocument()
+	{
+		return this.xmlDocument;
+	}
+
+	/**
+	 * Sets existing XML document for Libvirt XML node.
+	 * 
+	 * @param xmlDocument existing XML document.
+	 */
+	public void setXmlDocument( Document xmlDocument )
+	{
+		this.xmlDocument = xmlDocument;
+	}
+
+	/**
+	 * Returns current XML base node.
+	 * 
+	 * @return current XML base node as XML root anchor of relative internal XPath expressions.
+	 */
+	public Node getXmlBaseNode()
+	{
+		return this.xmlBaseNode;
+	}
+
+	/**
+	 * Sets existing XML base node for Libvirt XML node.
+	 * 
+	 * @param xmlBaseNode existing XML base node as XML root anchor for relative internal XPath
+	 *           expressions.
+	 */
+	public void setXmlBaseNode( Node xmlBaseNode )
+	{
+		this.xmlBaseNode = xmlBaseNode;
+	}
+
+	@Override
+	public Node getXmlNode( String expression )
+	{
+		if ( XPATH_EXPRESSION_CURRENT_NODE.equals( expression ) ) {
+			return this.xmlBaseNode;
+		}
+		NodeList nodes = this.getXmlNodes( expression );
+		return nodes.item( 0 );
+	}
+
+	@Override
+	public NodeList getXmlNodes( String expression )
+	{
+		Object nodes = null;
+
+		try {
+			XPath xPath = this.xPathFactory.newXPath();
+			XPathExpression xPathExpr = xPath.compile( expression );
+			nodes = xPathExpr.evaluate( this.xmlBaseNode, XPathConstants.NODESET );
+		} catch ( XPathExpressionException e ) {
+			e.printStackTrace();
+		}
+
+		return NodeList.class.cast( nodes );
+	}
+
+	@Override
+	public Element getXmlElement( String expression )
+	{
+		String completeExpression = null;
+
+		if ( expression == null || expression.isEmpty() ) {
+			completeExpression = XPATH_EXPRESSION_CURRENT_NODE;
+		} else {
+			completeExpression = XPATH_EXPRESSION_CURRENT_NODE + XPATH_EXPRESSION_SEPARATOR + expression;
+		}
+
+		Node node = this.getXmlNode( completeExpression );
+
+		if ( node != null && node.getNodeType() == Node.ELEMENT_NODE ) {
+			return (Element)node;
+		} else {
+			return null;
+		}
+	}
+
+	private Node createXmlElement( String expression )
+	{
+		Node parentNode = this.xmlBaseNode;
+		Node currentNode = parentNode;
+
+		if ( expression != null && !expression.isEmpty() ) {
+			String[] nodeNames = expression.split( XPATH_EXPRESSION_SEPARATOR );
+			String partialExpression = XPATH_EXPRESSION_CURRENT_NODE;
+
+			for ( int i = 0; i < nodeNames.length; i++ ) {
+				partialExpression += XPATH_EXPRESSION_SEPARATOR + nodeNames[i];
+				currentNode = this.getXmlNode( partialExpression );
+
+				if ( currentNode == null ) {
+					currentNode = this.xmlDocument.createElement( nodeNames[i] );
+					parentNode.appendChild( currentNode );
+				}
+
+				parentNode = currentNode;
+			}
+		}
+
+		return currentNode;
+	}
+
+	@Override
+	public void setXmlElement( String expression, Node child )
+	{
+		Node node = this.createXmlElement( expression );
+
+		if ( child != null ) {
+			node.appendChild( child );
+		}
+	}
+
+	@Override
+	public String getXmlElementValue( String expression )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node != null ) {
+			return node.getTextContent();
+		} else {
+			return null;
+		}
+	}
+
+	@Override
+	public void setXmlElementValue( String expression, String value )
+	{
+		Node node = this.createXmlElement( expression );
+		node.setTextContent( value );
+	}
+
+	@Override
+	public void removeXmlElement( String expression )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node != null ) {
+			node.getParentNode().removeChild( node );
+		}
+	}
+
+	@Override
+	public void removeXmlElementChilds( String expression )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node != null ) {
+			final NodeList childs = node.getChildNodes();
+			while ( childs.getLength() > 0 ) {
+				Node child = childs.item( 0 );
+				node.removeChild( child );
+			}
+		}
+	}
+
+	@Override
+	public String getXmlElementAttributeValue( String expression, String attributeName )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node == null ) {
+			return null;
+		} else {
+			Node attribute = node.getAttributes().getNamedItem( attributeName );
+
+			if ( attribute == null ) {
+				return null;
+			} else {
+				return attribute.getNodeValue();
+			}
+		}
+	}
+
+	@Override
+	public void setXmlElementAttributeValue( String expression, String attributeName, String value )
+	{
+		Node node = this.createXmlElement( expression );
+		Node attribute = node.getAttributes().getNamedItem( attributeName );
+
+		if ( attribute == null ) {
+			Element element = Element.class.cast( node );
+			element.setAttribute( attributeName, value );
+		} else {
+			attribute.setNodeValue( value );
+		}
+	}
+
+	@Override
+	public void removeXmlElementAttribute( String expression, String attributeName )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node != null ) {
+			Node attribute = node.getAttributes().getNamedItem( attributeName );
+			node.getAttributes().removeNamedItem( attribute.getNodeName() );
+		}
+	}
+
+	@Override
+	public void removeXmlElementAttributes( String expression )
+	{
+		Node node = this.getXmlElement( expression );
+
+		if ( node != null ) {
+			for ( int i = 0; i < node.getAttributes().getLength(); i++ ) {
+				Node attribute = node.getAttributes().item( 0 );
+				node.getAttributes().removeNamedItem( attribute.getNodeName() );
+			}
+		}
+	}
+
+	@Override
+	public void fromXmlNode( Node xmlNode )
+	{
+		this.setXmlBaseNode( xmlNode );
+	}
+
+	@Override
+	public Node toXmlNode()
+	{
+		return this.getXmlBaseNode();
+	}
+}