ingo@1022: /*
ingo@1022: * Copyright (c) 2010 by Intevation GmbH
ingo@1022: *
ingo@1022: * This program is free software under the LGPL (>=v2.1)
ingo@1022: * Read the file LGPL.txt coming with the software for details
ingo@1022: * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1022: */
ingo@1022:
tim@2: package de.intevation.gnv.util;
tim@2:
tim@2: import java.io.IOException;
tim@2: import java.io.InputStream;
ingo@670: import java.io.OutputStream;
tim@11: import java.io.StringBufferInputStream;
tim@2: import java.io.StringWriter;
tim@2:
tim@35: import javax.xml.namespace.NamespaceContext;
tim@35: import javax.xml.namespace.QName;
tim@2: import javax.xml.parsers.DocumentBuilder;
tim@2: import javax.xml.parsers.DocumentBuilderFactory;
tim@2: import javax.xml.parsers.ParserConfigurationException;
tim@2: import javax.xml.transform.Transformer;
tim@2: import javax.xml.transform.TransformerConfigurationException;
tim@2: import javax.xml.transform.TransformerException;
tim@2: import javax.xml.transform.TransformerFactory;
tim@2: import javax.xml.transform.TransformerFactoryConfigurationError;
tim@2: import javax.xml.transform.dom.DOMSource;
tim@2: import javax.xml.transform.stream.StreamResult;
tim@35: import javax.xml.xpath.XPath;
tim@35: import javax.xml.xpath.XPathConstants;
tim@35: import javax.xml.xpath.XPathExpressionException;
tim@35: import javax.xml.xpath.XPathFactory;
tim@2:
tim@2: import org.apache.log4j.Logger;
tim@35: import org.w3c.dom.Attr;
tim@35: import org.w3c.dom.Document;
tim@35: import org.w3c.dom.Element;
tim@35: import org.w3c.dom.Node;
tim@35: import org.w3c.dom.NodeList;
tim@35: import org.xml.sax.SAXException;
tim@2:
tim@2: /**
tim@962: * This class provides many helper-Methods for handling different kinds of
tim@962: * XML-stuff.
tim@962: * @author Tim Englich
tim@962: * @author Sascha L. Teichmann
tim@2: */
tim@36: public class XMLUtils {
tim@962:
tim@962: /**
tim@962: * the logger, used to log exceptions and additonaly information
tim@962: */
tim@2: private static Logger logger = Logger.getLogger(XMLUtils.class);
tim@2:
tim@962: /**
tim@962: * Constructor
tim@962: */
tim@2: public XMLUtils() {
tim@2: }
tim@2:
tim@962: /**
tim@962: * Class which could be used to create XML-Elements
tim@962: * @author Sascha L. Teichmann
tim@962: *
tim@962: */
tim@36: public static class ElementCreator {
tim@962:
tim@962: /**
tim@962: * The document the elements should be placed in.
tim@962: */
tim@2: protected Document document;
tim@962:
tim@962: /**
tim@962: * The namespace that should be used.
tim@962: */
tim@36: protected String ns;
tim@962:
tim@962: /**
tim@962: * The prefix of the namespace that should be used.
tim@962: */
tim@36: protected String prefix;
tim@2:
tim@962: /**
tim@962: * Constructor
tim@962: * @param document the document the elements should be placed in
tim@962: * @param ns the namespace that should be used
tim@962: * @param prefix the prefix of the namespace that should be used
tim@962: */
tim@2: public ElementCreator(Document document, String ns, String prefix) {
tim@2: this.document = document;
tim@36: this.ns = ns;
tim@36: this.prefix = prefix;
tim@2: }
tim@2:
tim@962: /**
tim@962: * Creates a new element using the given name.
tim@962: * @param name the name of the new element.
tim@962: * @return the new element
tim@962: */
tim@2: public Element create(String name) {
tim@2: Element element = document.createElementNS(ns, name);
tim@2: element.setPrefix(prefix);
tim@2: return element;
tim@2: }
tim@2:
tim@962: /**
tim@962: * Adds a new attribute to the given element.
tim@962: * @param element the element where the attribute should be placed in.
tim@962: * @param name the name of the attribute
tim@962: * @param value the value of the attribute
tim@962: */
tim@2: public void addAttr(Element element, String name, String value) {
tim@2: Attr attr = document.createAttributeNS(ns, name);
tim@2: attr.setValue(value);
tim@2: attr.setPrefix(prefix);
tim@2: element.setAttributeNode(attr);
tim@2: }
tim@2: } // class ElementCreator
tim@2:
tim@962: /**
tim@962: * Creates a new document.
tim@962: * @return the new document
tim@962: */
ingo@585: public static Document newDocument() {
tim@2: try {
tim@36: return DocumentBuilderFactory.newInstance().newDocumentBuilder()
tim@36: .newDocument();
tim@36: } catch (ParserConfigurationException pce) {
tim@2: logger.error(pce.getLocalizedMessage(), pce);
tim@2: }
tim@2: return null;
tim@2: }
tim@2:
tim@962: /**
tim@962: * Creates a new XPath-expression
tim@962: * @return the new XPath-expression
tim@962: */
ingo@585: public static XPath newXPath() {
tim@2: return newXPath(null);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Creates a new XPath-expression
tim@962: * @param namespaceContext the namespacecontext that should be used.
tim@962: * @return the new XPath-expression
tim@962: */
ingo@585: public static XPath newXPath(NamespaceContext namespaceContext) {
tim@2: XPathFactory factory = XPathFactory.newInstance();
tim@36: XPath xpath = factory.newXPath();
tim@2: if (namespaceContext != null) {
tim@2: xpath.setNamespaceContext(namespaceContext);
tim@2: }
tim@2: return xpath;
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch the value of an element or attribute from the given resource
tim@962: * using the query.
tim@962: * @param root the source where the value should be fetch from
tim@962: * @param query the query that should be used to fetch the value
tim@962: * @param namespaceContext the namespacecontext that must match to
tim@962: * fetch the value.
tim@962: * @return the value
tim@962: */
ingo@585: public static final String xpathString(Object root, String query,
tim@38: NamespaceContext namespaceContext) {
tim@36: return (String) xpath(root, query, XPathConstants.STRING,
tim@36: namespaceContext);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch the object rom the given resource using the query.
tim@962: * @param root the source where the value should be fetch from
tim@962: * @param query the query that should be used to fetch the object
tim@962: * @param returnType the Type that must be used to return the object,
tim@962: * @param namespaceContext the namespacecontext that must match to
tim@962: * fetch the object.
tim@962: * @return the value
tim@962: */
tim@36: public static final Object xpath(Object root, String query,
tim@38: QName returnType,
tim@38: NamespaceContext namespaceContext) {
tim@2: if (root == null) {
tim@2: return null;
tim@2: }
tim@2: try {
tim@962: XPath xpath = XMLUtils.newXPath(namespaceContext);
tim@2: if (xpath != null) {
tim@2: return xpath.evaluate(query, root, returnType);
tim@2: }
tim@36: } catch (XPathExpressionException xpee) {
tim@2: logger.error(xpee.getLocalizedMessage(), xpee);
tim@35: }
tim@2: return null;
tim@2: }
tim@36:
tim@962: /**
tim@962: * Fetch the object rom the given resource using the query
tim@962: * and the default ArtifactNamespaceContext
tim@962: * @param root the source where the value should be fetch from
tim@962: * @param query the query that should be used to fetch the object
tim@962: * @param returnType the Type that must be used to return the object
tim@962: * @return the value
tim@962: */
ingo@585: public static Object getXPath(Object root, String query, QName returnType) {
ingo@389: return getXPath(root,query,returnType,ArtifactNamespaceContext.INSTANCE);
ingo@389: }
ingo@389:
tim@962: /**
tim@962: * Fetch the object rom the given resource using the query
tim@962: * and the default ArtifactNamespaceContext
tim@962: * @param root the source where the value should be fetch from
tim@962: * @param query the query that should be used to fetch the object
tim@962: * @param returnType the Type that must be used to return the object.
tim@964: * @param context the namespacecontext that must match to
tim@962: * fetch the object.
tim@962: * @return the value
tim@962: */
ingo@585: public static Object getXPath(
ingo@389: Object root, String query, QName returnType, NamespaceContext context
ingo@389: ) {
ingo@389: return xpath(root, query, returnType, context);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch a Nodeset value from a XML-Fragment or XML-Document using the
tim@962: * given query.
tim@962: * @param root the source where the String should be fetched from
tim@962: * @param query the query that should be used,
tim@962: * @return the Nodeset fetched from the source
tim@962: */
ingo@585: public static NodeList getNodeSetXPath(Object root, String query) {
tim@36: return (NodeList) getXPath(root, query, XPathConstants.NODESET);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch a Node from a XML-Fragment or XML-Document using the
tim@962: * given query.
tim@962: * @param root the source where the Node should be fetched from
tim@962: * @param query the query that should be used,
tim@962: * @return the Node fetched from the source
tim@962: */
ingo@585: public static Node getNodeXPath(Object root, String query) {
tim@36: return (Node) getXPath(root, query, XPathConstants.NODE);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch a String value from a XML-Fragment or XML-Document using the
tim@962: * given query.
tim@962: * @param root the source where the String should be fetched from
tim@962: * @param xpath the query that should be used,
tim@962: * @return the String fetched from the source
tim@962: */
ingo@585: public static String getStringXPath(Object root, String xpath) {
tim@2: return getStringXPath(root, xpath, null);
tim@2: }
tim@2:
tim@962: /**
tim@962: * Fetch a String value from a XML-Fragment or XML-Document using the
tim@962: * given query.
tim@962: * @param root the source where the String should be fetched from
tim@962: * @param query the query that should be used,
tim@962: * @param def the default-value that will be returned id no value was found
tim@962: * @return the String fetched from the source
tim@962: */
ingo@585: public static String getStringXPath(Object root, String query, String def) {
tim@36: String s = (String) getXPath(root, query, XPathConstants.STRING);
tim@36: return s == null || s.length() == 0 ? def : s;
tim@2: }
tim@36:
tim@962: /**
tim@962: * Reads an XML-document from a given InputStream
tim@962: * @param inputStream the InputStream where the document
tim@962: * should be read from
tim@962: * @return the document that could be read.
tim@962: */
ingo@570: public static Document readDocument(InputStream inputStream) {
tim@2: Document returnValue = null;
tim@2: try {
tim@36: DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory
tim@36: .newInstance();
ingo@389: docBuilderFactory.setNamespaceAware(true);
tim@2: DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
tim@36: returnValue = docBuilder.parse(inputStream);
tim@2: } catch (ParserConfigurationException e) {
tim@36: logger.error(e, e);
tim@2: } catch (SAXException e) {
tim@36: logger.error(e, e);
tim@2: } catch (IOException e) {
tim@36: logger.error(e, e);
tim@2: }
tim@2: return returnValue;
tim@2: }
tim@36:
tim@962: /**
tim@962: * Writes an single XML-Node to a string
tim@962: * @param node the XML-Node that should be written
tim@962: * @return the encoded XML-Node
tim@962: */
ingo@585: public static String writeNode2String(Node node) {
tim@2: try {
tim@11: DOMSource source = new DOMSource(node);
tim@11: return writeDOMSource2String(source);
tim@2: } catch (TransformerConfigurationException e) {
tim@36: logger.error(e, e);
tim@2: } catch (TransformerFactoryConfigurationError e) {
tim@36: logger.error(e, e);
tim@2: } catch (TransformerException e) {
tim@36: logger.error(e, e);
tim@2: }
tim@2: return null;
tim@2: }
tim@36:
tim@962: /**
tim@962: * Reinitialize the doument.
tim@962: * This is neccessary because the namespace sometimes is invalid
tim@962: * using a document which was created and used in the same step.
tim@962: * @param document the document which should be reinitialize
tim@962: * @return the document
tim@962: */
ingo@585: public static Document reInitDocument(Document document) {
ingo@585: StringBufferInputStream inputStream = new StringBufferInputStream(
ingo@585: writeDocument2String(document));
ingo@585: return readDocument(inputStream);
tim@11: }
tim@36:
tim@962: /**
tim@962: * Writes the given Document into a String.
tim@962: * This is very helpful for debugging.
tim@962: * @param document the document which should be written to the string.
tim@962: * @return the encoded xml-document.
tim@962: */
ingo@585: public static String writeDocument2String(Document document) {
tim@11: try {
tim@11: DOMSource source = new DOMSource(document);
tim@11: return writeDOMSource2String(source);
tim@11: } catch (TransformerConfigurationException e) {
tim@36: logger.error(e, e);
tim@11: } catch (TransformerFactoryConfigurationError e) {
tim@36: logger.error(e, e);
tim@11: } catch (TransformerException e) {
tim@36: logger.error(e, e);
tim@11: }
tim@11: return null;
tim@11: }
tim@11:
tim@11: /**
tim@962: * Writes a given DOMSource into a String
tim@962: * @param source the source that should be written to string
tim@962: * @return the encoded DOMSource
tim@11: * @throws TransformerFactoryConfigurationError
tim@11: * @throws TransformerConfigurationException
tim@11: * @throws TransformerException
tim@11: */
ingo@585: private static String writeDOMSource2String(DOMSource source)
tim@38: throws TransformerFactoryConfigurationError,
tim@38: TransformerConfigurationException,
tim@38: TransformerException {
tim@36: TransformerFactory transformerFactory = TransformerFactory
tim@36: .newInstance();
tim@11: Transformer transformer = transformerFactory.newTransformer();
tim@11: StringWriter sw = new StringWriter();
tim@36: StreamResult result = new StreamResult(sw);
tim@11: transformer.transform(source, result);
tim@11: return sw.getBuffer().toString();
tim@11: }
ingo@670:
tim@962: /**
tim@962: * Writes a given Document to an OutputStream
tim@962: * @param document the document that should be written
tim@962: * @param out the stream where the document should be written to,
tim@962: * @return true if it was successful, false if not.
tim@962: */
tim@962: public static boolean toStream(Document document, OutputStream out) {
ingo@670: try {
ingo@670: Transformer transformer =
ingo@670: TransformerFactory.newInstance().newTransformer();
ingo@670: DOMSource source = new DOMSource(document);
ingo@670: StreamResult result = new StreamResult(out);
ingo@670: transformer.transform(source, result);
ingo@670: return true;
ingo@670: }
ingo@670: catch (TransformerConfigurationException tce) {
ingo@670: logger.error(tce.getLocalizedMessage(), tce);
ingo@670: }
ingo@670: catch (TransformerFactoryConfigurationError tfce) {
ingo@670: logger.error(tfce.getLocalizedMessage(), tfce);
ingo@670: }
ingo@670: catch (TransformerException te) {
ingo@670: logger.error(te.getLocalizedMessage(), te);
ingo@670: }
ingo@670: return false;
sascha@681: }
tim@2: }
tim@2: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8: