import java.io.ByteArrayInputStream;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.util.List;import java.util.Vector;import javax.naming.ConfigurationException;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.FactoryConfigurationError;import javax.xml.parsers.ParserConfigurationException;import javax.xml.transform.OutputKeys;import javax.xml.transform.Transformer;import javax.xml.transform.TransformerFactory;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;import javax.xml.xpath.XPath;import javax.xml.xpath.XPathConstants;import javax.xml.xpath.XPathExpressionException;import javax.xml.xpath.XPathFactory;import org.w3c.dom.Attr;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.NamedNodeMap;import org.w3c.dom.Node;import org.w3c.dom.NodeList;import org.xml.sax.SAXException;/** * DOM utility * * Thanks to Tom Fennelly from Jboss Group * */public class DOMUtil {/** * Create a new W3C Document. * <p/> * Handles exceptions etc. * @return The new Document instance. * @throws ConfigurationException */public static Document createDocument() throws ConfigurationException {Document doc = null;try {doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();} catch (ParserConfigurationException e) {throw new ConfigurationException("Failed to create ESB Configuration Document instance.");}return doc;} /** * Parse the supplied XML String and return the associated W3C Document object. * * @param xml XML String. * @return The W3C Document object associated with the input stream. */ public static Document parse(String xml) throws SAXException, IOException { return parseStream(new ByteArrayInputStream(xml.getBytes()), false, false); } /** * Parse the XML stream and return the associated W3C Document object. * <p/> * Performs a namespace unaware parse. * * @param stream * The stream to be parsed. * @param validate * True if the document is to be validated, otherwise false. * @param expandEntityRefs * Expand entity References as per * {@link DocumentBuilderFactory#setExpandEntityReferences(boolean)}. * @return The W3C Document object associated with the input stream. */ public static Document parseStream(InputStream stream, boolean validate, boolean expandEntityRefs) throws SAXException, IOException { return parseStream(stream, validate, expandEntityRefs, false); } /** * Parse the XML stream and return the associated W3C Document object. * * @param stream * The stream to be parsed. * @param validate * True if the document is to be validated, otherwise false. * @param expandEntityRefs * Expand entity References as per * {@link DocumentBuilderFactory#setExpandEntityReferences(boolean)}. * @param namespaceAware * True if the document parse is to be namespace aware, * otherwise false. * @return The W3C Document object associated with the input stream. */ public static Document parseStream(InputStream stream, boolean validate, boolean expandEntityRefs, boolean namespaceAware) throws SAXException, IOException { if (stream == null) { throw new IllegalArgumentException( "null 'stream' arg in method call."); } try { DocumentBuilderFactory factory = DocumentBuilderFactory .newInstance(); DocumentBuilder docBuilder = null; factory.setValidating(validate); factory.setExpandEntityReferences(expandEntityRefs); factory.setNamespaceAware(namespaceAware); docBuilder = factory.newDocumentBuilder(); return docBuilder.parse(stream); } catch (ParserConfigurationException e) { IllegalStateException state = new IllegalStateException( "Unable to parse XML stream - XML Parser not configured correctly."); state.initCause(e); throw state; } catch (FactoryConfigurationError e) { IllegalStateException state = new IllegalStateException( "Unable to parse XML stream - DocumentBuilderFactory not configured correctly."); state.initCause(e); throw state; } } public static String getAttribute(Element element, String name, String defaultVal) { if(element.hasAttribute(name)) { return element.getAttribute(name); } else { return defaultVal; } } /** * Add an Element node to the supplied parent name. * @param parent The parent to to which the new Element node is to be added. * @param elementName The name of the Element to be added. * @return The new Element. */public static Element addElement(Node parent, String elementName) {Element element = null;if(parent instanceof Document) {element = ((Document)parent).createElement(elementName);} else {element = parent.getOwnerDocument().createElement(elementName);}parent.appendChild(element);return element;}/** * Remove all attributes having an empty value. * @param element The element to be processed. */public static void removeEmptyAttributes(Element element) {NamedNodeMap attributes = element.getAttributes();int attribCount = attributes.getLength();for(int i = attribCount - 1; i >= 0; i--) {Attr attribute = (Attr) attributes.item(i);// Note - doesn't account for namespaces. Not needed here !if(attribute.getValue().equals("")) {attributes.removeNamedItem(attribute.getName());}}}/** * Serialize the supplied DOM node to the specified file in the specified output directory. * @param node The DOM node to be serialised. * @param outdir The directory into which the file is to be serialised. * @param fileName The name of the file. * @throws ConfigurationException Unable to serialise the node. */public static void serialize(Node node, File outdir, String fileName) throws ConfigurationException {serialize(node, new StreamResult(new File(outdir, fileName)));} public static void serialize(Node node, OutputStream out) throws ConfigurationException { serialize(node, new StreamResult(out)); } /** * Serialize the supplied DOM node to the supplied DOM StreamResult instance. * @param node The DOM node to be serialised. * @param streamRes The StreamResult into which the node is to be serialised. * @throws ConfigurationException Unable to serialise the node. */ public static void serialize(Node node, StreamResult streamRes) throws ConfigurationException { serialize(node, streamRes, false); } /** * Serialize the supplied DOM node to the supplied DOM StreamResult instance. * @param node The DOM node to be serialised. * @param streamRes The StreamResult into which the node is to be serialised. * @param omitXmlDecl Omit the XML declaration. * @throws ConfigurationException Unable to serialise the node. */public static void serialize(Node node, StreamResult streamRes, boolean omitXmlDecl) throws ConfigurationException {DOMSource domSource = new DOMSource(node);try {Transformer transformer = TransformerFactory.newInstance().newTransformer(); // There's a bug in Java 5 re this code (formatting). // See http://forum.java.sun.com/thread.jspa?threadID=562510&start=0 and it explains the // whys of the following code. // transformer.setOutputProperty("{http://xml.apache.org/xalan}indent-amount", "4");transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, (omitXmlDecl?"yes":"no"));transformer.transform(domSource, streamRes);} catch (Exception e) {throw new ConfigurationException("Failed to serialize ESB Configuration Document instance.");}} /** * Count the DOM element nodes before the supplied node, having the specified * tag name, not including the node itself. * <p/> * Counts the sibling nodes. * * @param node Node whose element siblings are to be counted. * @param tagName The tag name of the sibling elements to be counted. * @return The number of siblings elements before the supplied node with the * specified tag name. */ public static int countElementsBefore(Node node, String tagName) { Node parent = node.getParentNode(); NodeList siblings = parent.getChildNodes(); int count = 0; int siblingCount = siblings.getLength(); for (int i = 0; i < siblingCount; i++) { Node sibling = siblings.item(i); if (sibling == node) { break; } if (sibling.getNodeType() == Node.ELEMENT_NODE && ((Element) sibling).getTagName().equals(tagName)) { count++; } } return count; } /** * Copy the nodes of a NodeList into the supplied list. * <p/> * This is not a cloneCollectionTemplateElement. It's just a copy of the node references. * <p/> * Allows iteration over the Nodelist using the copy in the knowledge that * the list will remain the same length, even if we modify the underlying NodeList. * Using the NodeList can result in problems because elements can get removed from * the list while we're iterating over it. * <p/> * <i>This code was acquired donated by the Milyn Smooks project.</i> * * @param nodeList Nodelist to copy. * @return List copy. */ public static List<Node> copyNodeList(NodeList nodeList) { List<Node> copy = new Vector<Node>(); if (nodeList != null) { int nodeCount = nodeList.getLength(); for (int i = 0; i < nodeCount; i++) { copy.add(nodeList.item(i)); } } return copy; } public static Element getNextSiblingElement(Node node) { Node nextSibling = node.getNextSibling(); while (nextSibling != null) { if (nextSibling.getNodeType() == Node.ELEMENT_NODE) { return (Element) nextSibling; } nextSibling = nextSibling.getNextSibling(); } return null; } public static Node getFirstChildByType(Element element, int nodeType) { NodeList children = element.getChildNodes(); int childCount = children.getLength(); for(int i = 0; i < childCount; i++) { Node child = children.item(i); if (child.getNodeType() == nodeType) { return child; } } return null; } private static String ELEMENT_NAME_FUNC = "/name()"; private static XPathFactory xPathFactory = XPathFactory.newInstance(); /** * Get the W3C NodeList instance associated with the XPath selection * supplied. * <p/> * <b>NOTE</b>: Taken from Milyn Commons. * * @param node The document node to be searched. * @param xpath The XPath String to be used in the selection. * @return The W3C NodeList instance at the specified location in the * document, or null. */ public static NodeList getNodeList(Node node, String xpath) { if (node == null) { throw new IllegalArgumentException( "null 'document' arg in method call."); } else if (xpath == null) { throw new IllegalArgumentException( "null 'xpath' arg in method call."); } try { XPath xpathEvaluater = xPathFactory.newXPath(); if (xpath.endsWith(ELEMENT_NAME_FUNC)) { return (NodeList) xpathEvaluater.evaluate(xpath.substring(0, xpath.length() - ELEMENT_NAME_FUNC.length()), node, XPathConstants.NODESET); } else { return (NodeList) xpathEvaluater.evaluate(xpath, node, XPathConstants.NODESET); } } catch (XPathExpressionException e) { throw new IllegalArgumentException("bad 'xpath' expression [" + xpath + "]."); } } /** * Get the W3C Node instance associated with the XPath selection supplied. * <p/> * <b>NOTE</b>: Taken from Milyn Commons. * * @param node The document node to be searched. * @param xpath The XPath String to be used in the selection. * @return The W3C Node instance at the specified location in the document, * or null. */ public static Node getNode(Node node, String xpath) { NodeList nodeList = getNodeList(node, xpath); if (nodeList == null || nodeList.getLength() == 0) { return null; } else { return nodeList.item(0); } } /** * Get the name from the supplied element. * <p/> * Returns the {@link Node#getLocalName() localName} of the element * if set (namespaced element), otherwise the * element's {@link Element#getTagName() tagName} is returned. * <p/> * <b>NOTE</b>: Taken from Milyn Smooks. * * @param element The element. * @return The element name. */ public static String getName(Element element) { String name = element.getLocalName(); if(name != null) { return name; } else { return element.getTagName(); } } /** * Copy child node references from source to target. * @param source Source Node. * @param target Target Node. */ public static void copyChildNodes(Node source, Node target) { List nodeList = copyNodeList(source.getChildNodes()); int childCount = nodeList.size(); for(int i = 0; i < childCount; i++) { target.appendChild((Node)nodeList.get(i)); } }}
