rrenkert@27: /*
rrenkert@27: * Copyright (c) 2010 by Intevation GmbH
rrenkert@27: *
rrenkert@27: * This program is free software under the LGPL (>=v2.1)
rrenkert@27: * Read the file LGPL.txt coming with the software for details
rrenkert@27: * or visit http://www.gnu.org/licenses/ if it does not exist.
rrenkert@27: */
rrenkert@27:
rrenkert@33: package de.intevation.mxd.utils;
rrenkert@27:
rrenkert@27: import java.io.ByteArrayInputStream;
rrenkert@27: import java.io.FileInputStream;
rrenkert@27: import java.io.BufferedInputStream;
rrenkert@27: import java.io.ByteArrayOutputStream;
rrenkert@27: import java.io.File;
rrenkert@27: import java.io.IOException;
rrenkert@27: import java.io.InputStream;
rrenkert@27: import java.io.OutputStream;
rrenkert@27:
rrenkert@27: import javax.xml.namespace.NamespaceContext;
rrenkert@27: import javax.xml.namespace.QName;
rrenkert@27:
rrenkert@27: import javax.xml.parsers.DocumentBuilderFactory;
rrenkert@27: import javax.xml.parsers.ParserConfigurationException;
rrenkert@27:
rrenkert@27: import javax.xml.transform.Transformer;
rrenkert@27: import javax.xml.transform.TransformerConfigurationException;
rrenkert@27: import javax.xml.transform.TransformerException;
rrenkert@27: import javax.xml.transform.TransformerFactory;
rrenkert@27: import javax.xml.transform.TransformerFactoryConfigurationError;
rrenkert@27:
rrenkert@27: import javax.xml.transform.dom.DOMSource;
rrenkert@27:
rrenkert@27: import javax.xml.transform.stream.StreamResult;
rrenkert@27:
rrenkert@27: import javax.xml.xpath.XPath;
rrenkert@27: import javax.xml.xpath.XPathConstants;
rrenkert@27: import javax.xml.xpath.XPathExpressionException;
rrenkert@27: import javax.xml.xpath.XPathFactory;
rrenkert@27:
rrenkert@27: import org.apache.log4j.Logger;
rrenkert@27:
rrenkert@27: import org.w3c.dom.Attr;
rrenkert@27: import org.w3c.dom.Document;
rrenkert@27: import org.w3c.dom.Element;
rrenkert@27:
rrenkert@27: import org.xml.sax.SAXException;
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Some helper functions to ease work with XML concering namespaces, XPATH
rrenkert@27: * and so on.
rrenkert@27: * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
rrenkert@27: */
rrenkert@27: public final class XMLUtils
rrenkert@27: {
rrenkert@27: /**
rrenkert@27: * W3C URL of XForms
rrenkert@27: */
rrenkert@27: public static final String XFORM_URL = "http://www.w3.org/2002/xforms";
rrenkert@27: /**
rrenkert@27: * W3C prefix of XForms
rrenkert@27: */
rrenkert@27: public static final String XFORM_PREFIX = "xform";
rrenkert@27:
rrenkert@27: private static Logger logger = Logger.getLogger(XMLUtils.class);
rrenkert@27:
rrenkert@27: private XMLUtils() {
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Helper class to generate elements and attributes with
rrenkert@27: * namespaces.
rrenkert@27: */
rrenkert@27: public static class ElementCreator
rrenkert@27: {
rrenkert@27: /**
rrenkert@27: * owner document of the elements to be created
rrenkert@27: */
rrenkert@27: protected Document document;
rrenkert@27: /**
rrenkert@27: * namespace to be used
rrenkert@27: */
rrenkert@27: protected String ns;
rrenkert@27: /**
rrenkert@27: * prefix to be used
rrenkert@27: */
rrenkert@27: protected String prefix;
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Constructor to create an element/attribute creator
rrenkert@27: * with a given namespace and namespace prefix using a
rrenkert@27: * given owner document.
rrenkert@27: * @param document The owning document
rrenkert@27: * @param ns The namespace
rrenkert@27: * @param prefix The namespace prefix
rrenkert@27: */
rrenkert@27: public ElementCreator(Document document, String ns, String prefix) {
rrenkert@27: this.document = document;
rrenkert@27: this.ns = ns;
rrenkert@27: this.prefix = prefix;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Creates a new element using the owning document with
rrenkert@27: * the this creators namespace and namespace prefix.
rrenkert@27: * @param name The name of the element
rrenkert@27: * @return The new element
rrenkert@27: */
rrenkert@27: public Element create(String name) {
rrenkert@27: Element element = document.createElementNS(ns, name);
rrenkert@27: element.setPrefix(prefix);
rrenkert@27: return element;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Adds a new attribute and its value to a given element.
rrenkert@27: * It does not set the namespace prefix.
rrenkert@27: * @param element The element to add the attribute to
rrenkert@27: * @param name The name of the attribute
rrenkert@27: * @param value The value of the attribute
rrenkert@27: */
rrenkert@27: public void addAttr(Element element, String name, String value) {
rrenkert@27: addAttr(element, name, value, false);
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Adds a new attribute and its value to a given element.
rrenkert@27: * If the namespace prefix is used is decided by the 'addPrefix' flag.
rrenkert@27: * @param element The element to add the attribute to
rrenkert@27: * @param name The name of the attribute
rrenkert@27: * @param value The value of the attribute
rrenkert@27: * @param addPrefix If true the creators namespace prefix is
rrenkert@27: * set on the attribute.
rrenkert@27: */
rrenkert@27: public void addAttr(
rrenkert@27: Element element,
rrenkert@27: String name,
rrenkert@27: String value,
rrenkert@27: boolean addPrefix
rrenkert@27: ) {
rrenkert@27: if (addPrefix) {
rrenkert@27: Attr attr = document.createAttributeNS(ns, name);
rrenkert@27: attr.setValue(value);
rrenkert@27: attr.setPrefix(prefix);
rrenkert@27:
rrenkert@27: element.setAttributeNode(attr);
rrenkert@27: }
rrenkert@27: else {
rrenkert@27: element.setAttribute(name, value);
rrenkert@27: }
rrenkert@27:
rrenkert@27: }
rrenkert@27: } // class ElementCreator
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Creates a new XML document
rrenkert@27: * @return the new XML document ot null if something went wrong during
rrenkert@27: * creation.
rrenkert@27: */
rrenkert@27: public static final Document newDocument() {
rrenkert@27: DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
rrenkert@27: factory.setNamespaceAware(true);
rrenkert@27:
rrenkert@27: try {
rrenkert@27: return factory.newDocumentBuilder().newDocument();
rrenkert@27: }
rrenkert@27: catch (ParserConfigurationException pce) {
rrenkert@27: logger.error(pce.getLocalizedMessage(), pce);
rrenkert@27: }
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Loads a XML document namespace aware from a file
rrenkert@27: * @param file The file to load.
rrenkert@27: * @return the XML document or null if something went wrong
rrenkert@27: * during loading.
rrenkert@27: */
rrenkert@27: public static final Document parseDocument(File file) {
rrenkert@27: InputStream inputStream = null;
rrenkert@27: try {
rrenkert@27: inputStream = new BufferedInputStream(new FileInputStream(file));
rrenkert@27: return parseDocument(inputStream);
rrenkert@27: }
rrenkert@27: catch (IOException ioe) {
rrenkert@27: logger.error(ioe.getLocalizedMessage(), ioe);
rrenkert@27: }
rrenkert@27: finally {
rrenkert@27: if (inputStream != null) {
rrenkert@27: try { inputStream.close(); }
rrenkert@27: catch (IOException ioe) {}
rrenkert@27: }
rrenkert@27: }
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: public static final Document parseDocument(InputStream inputStream) {
rrenkert@27: DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
rrenkert@27: factory.setNamespaceAware(true);
rrenkert@27:
rrenkert@27: try {
rrenkert@27: return factory.newDocumentBuilder().parse(inputStream);
rrenkert@27: }
rrenkert@27: catch (ParserConfigurationException pce) {
rrenkert@27: logger.error(pce.getLocalizedMessage(), pce);
rrenkert@27: }
rrenkert@27: catch (SAXException se) {
rrenkert@27: logger.error(se.getLocalizedMessage(), se);
rrenkert@27: }
rrenkert@27: catch (IOException ioe) {
rrenkert@27: logger.error(ioe.getLocalizedMessage(), ioe);
rrenkert@27: }
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Creates a new XPath without a namespace context.
rrenkert@27: * @return the new XPath.
rrenkert@27: */
rrenkert@27: public static final XPath newXPath() {
rrenkert@27: return newXPath(null);
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Creates a new XPath with a given namespace context.
rrenkert@27: * @param namespaceContext The namespace context to be used or null
rrenkert@27: * if none should be used.
rrenkert@27: * @return The new XPath
rrenkert@27: */
rrenkert@27: public static final XPath newXPath(NamespaceContext namespaceContext) {
rrenkert@27: XPathFactory factory = XPathFactory.newInstance();
rrenkert@27: XPath xpath = factory.newXPath();
rrenkert@27: if (namespaceContext != null) {
rrenkert@27: xpath.setNamespaceContext(namespaceContext);
rrenkert@27: }
rrenkert@27: return xpath;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Evaluates an XPath query on a given object and returns the result
rrenkert@27: * as a given type. No namespace context is used.
rrenkert@27: * @param root The object which is used as the root of the tree to
rrenkert@27: * be searched in.
rrenkert@27: * @param query The XPath query
rrenkert@27: * @param returnTyp The type of the result.
rrenkert@27: * @return The result of type 'returnTyp' or null if something
rrenkert@27: * went wrong during XPath evaluation.
rrenkert@27: */
rrenkert@27: public static final Object xpath(
rrenkert@27: Object root,
rrenkert@27: String query,
rrenkert@27: QName returnTyp
rrenkert@27: ) {
rrenkert@27: return xpath(root, query, returnTyp, null);
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Evaluates an XPath query on a given object and returns the result
rrenkert@27: * as a string. A given namespace context is used.
rrenkert@27: * @param root The object which is used as the root of the tree to
rrenkert@27: * be searched in.
rrenkert@27: * @param query The XPath query
rrenkert@27: * @param namespaceContext The namespace context to be used or null
rrenkert@27: * if none should be used.
rrenkert@27: * @return The result of the query or null if something went wrong
rrenkert@27: * during XPath evaluation.
rrenkert@27: */
rrenkert@27: public static final String xpathString(
rrenkert@27: Object root, String query, NamespaceContext namespaceContext
rrenkert@27: ) {
rrenkert@27: return (String)xpath(
rrenkert@27: root, query, XPathConstants.STRING, namespaceContext);
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Evaluates an XPath query on a given object and returns the result
rrenkert@27: * as a given type. Optionally a namespace context is used.
rrenkert@27: * @param root The object which is used as the root of the tree to
rrenkert@27: * be searched in.
rrenkert@27: * @param query The XPath query
rrenkert@27: * @param returnType The type of the result.
rrenkert@27: * @param namespaceContext The namespace context to be used or null
rrenkert@27: * if none should be used.
rrenkert@27: * @return The result of type 'returnTyp' or null if something
rrenkert@27: * went wrong during XPath evaluation.
rrenkert@27: */
rrenkert@27: public static final Object xpath(
rrenkert@27: Object root,
rrenkert@27: String query,
rrenkert@27: QName returnType,
rrenkert@27: NamespaceContext namespaceContext
rrenkert@27: ) {
rrenkert@27: if (root == null) {
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: try {
rrenkert@27: XPath xpath = newXPath(namespaceContext);
rrenkert@27: if (xpath != null) {
rrenkert@27: return xpath.evaluate(query, root, returnType);
rrenkert@27: }
rrenkert@27: }
rrenkert@27: catch (XPathExpressionException xpee) {
rrenkert@27: logger.error(xpee.getLocalizedMessage(), xpee);
rrenkert@27: }
rrenkert@27:
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Streams out an XML document to a given output stream.
rrenkert@27: * @param document The document to be streamed out.
rrenkert@27: * @param out The output stream to be used.
rrenkert@27: * @return true if operation succeeded else false.
rrenkert@27: */
rrenkert@27: public static boolean toStream(Document document, OutputStream out) {
rrenkert@27: try {
rrenkert@27: Transformer transformer =
rrenkert@27: TransformerFactory.newInstance().newTransformer();
rrenkert@27: DOMSource source = new DOMSource(document);
rrenkert@27: StreamResult result = new StreamResult(out);
rrenkert@27: transformer.transform(source, result);
rrenkert@27: return true;
rrenkert@27: }
rrenkert@27: catch (TransformerConfigurationException tce) {
rrenkert@27: logger.error(tce.getLocalizedMessage(), tce);
rrenkert@27: }
rrenkert@27: catch (TransformerFactoryConfigurationError tfce) {
rrenkert@27: logger.error(tfce.getLocalizedMessage(), tfce);
rrenkert@27: }
rrenkert@27: catch (TransformerException te) {
rrenkert@27: logger.error(te.getLocalizedMessage(), te);
rrenkert@27: }
rrenkert@27:
rrenkert@27: return false;
rrenkert@27: }
rrenkert@27:
rrenkert@27: /**
rrenkert@27: * Transforms an XML document into a byte array.
rrenkert@27: * @param document The document to be streamed out.
rrenkert@27: * @return the byte array or null if operation failed or
rrenkert@27: * document is null.
rrenkert@27: */
rrenkert@27: public static byte [] toByteArray(Document document) {
rrenkert@27: if (document == null) {
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27: ByteArrayOutputStream baos = new ByteArrayOutputStream();
rrenkert@27: return toStream(document, baos)
rrenkert@27: ? baos.toByteArray()
rrenkert@27: : null;
rrenkert@27: }
rrenkert@27:
rrenkert@27: public static Document fromByteArray(byte [] data) {
rrenkert@27: if (data == null) {
rrenkert@27: return null;
rrenkert@27: }
rrenkert@27: return parseDocument(new ByteArrayInputStream(data));
rrenkert@27: }
rrenkert@27: }
rrenkert@27: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :