Java tutorial
/* * Copyright 2015-2016 OpenEstate.org. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.openestate.io.immobiliare_it; import javax.xml.bind.JAXBException; import javax.xml.parsers.ParserConfigurationException; import org.apache.commons.lang3.StringUtils; import org.jaxen.JaxenException; import org.openestate.io.core.XmlConvertableDocument; import org.openestate.io.core.XmlUtils; import org.openestate.io.immobiliare_it.xml.Feed; import org.openestate.io.immobiliare_it.xml.Version; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; /** * XML document from <a href="http://immobiliare.it/">immobiliare.it</a> with a * <feed> root element. * * @since 1.0 * @author Andreas Rudolph */ public class ImmobiliareItDocument extends XmlConvertableDocument<Feed, ImmobiliareItVersion> { private final static Logger LOGGER = LoggerFactory.getLogger(ImmobiliareItDocument.class); /** * Create from a {@link Document}. * * @param document * the document to create from */ public ImmobiliareItDocument(Document document) { super(document); if (!isReadable(document)) throw new IllegalArgumentException("The provided document is invalid!"); } @Override public ImmobiliareItVersion getDocumentVersion() { String version; try { Document doc = this.getDocument(); version = StringUtils .trimToNull(XmlUtils.newXPath("/io:feed/io:version/text()", doc).stringValueOf(doc)); if (version == null) { LOGGER.warn("Can't find version informations in the XML document!"); //System.out.println( "----------------------------" ); //try //{ // DocumentUtils.write( doc, System.out ); //} //catch (Exception ex) //{ // LOGGER.error( "Can't write XML document!" ); // LOGGER.error( "> " + ex.getLocalizedMessage(), ex ); //} //System.out.println( "----------------------------" ); return null; } } catch (JaxenException ex) { LOGGER.error("Can't evaluate XPath expression!"); LOGGER.error("> " + ex.getLocalizedMessage(), ex); return null; } ImmobiliareItVersion v = ImmobiliareItVersion.detectFromString(version); if (v != null) return v; LOGGER.warn("The provided version (" + version + ") is not supported!"); return null; } @Override public ImmobiliareItVersion getLatestVersion() { return ImmobiliareItUtils.VERSION; } /** * Checks, if a {@link Document} is readable as a * {@link ImmobiliareItDocument}. * * @param doc * document to check * * @return * true, if the document is usable, otherwise false */ public static boolean isReadable(Document doc) { Element root = XmlUtils.getRootElement(doc); return "feed".equals(root.getLocalName()); } /** * Creates an empty {@link ImmobiliareItDocument}. * * @return * created document * * @throws ParserConfigurationException * if the parser is not properly configured * * @throws JAXBException * if a problem with JAXB occured */ public static ImmobiliareItDocument newDocument() throws ParserConfigurationException, JAXBException { return newDocument(ImmobiliareItUtils.getFactory().createFeed()); } /** * Creates a {@link ImmobiliareItDocument} from a {@link Feed} object. * * @param feed * Java object, that represents the <feed> root element * * @return * created document * * @throws ParserConfigurationException * if the parser is not properly configured * * @throws JAXBException * if a problem with JAXB occured */ public static ImmobiliareItDocument newDocument(Feed feed) throws ParserConfigurationException, JAXBException { if (feed.getVersion() == null) feed.setVersion(Version.V2_5); Document document = XmlUtils.newDocument(); ImmobiliareItUtils.createMarshaller("UTF-8", true).marshal(feed, document); return new ImmobiliareItDocument(document); } @Override public void setDocumentVersion(ImmobiliareItVersion version) { try { Document doc = this.getDocument(); Element node = (Element) XmlUtils.newXPath("/io:feed/io:version", doc).selectSingleNode(doc); if (node == null) { Element parentNode = (Element) XmlUtils.newXPath("/io:feed", doc).selectSingleNode(doc); if (parentNode == null) { LOGGER.warn("Can't find a <feed> element in the document!"); return; } node = doc.createElement("version"); parentNode.insertBefore(node, parentNode.getFirstChild()); } node.setTextContent(version.toReadableVersion()); } catch (JaxenException ex) { LOGGER.error("Can't evaluate XPath expression!"); LOGGER.error("> " + ex.getLocalizedMessage(), ex); } } /** * Creates a {@link Feed} object from the contained {@link Document}. * * @return * created object, that represents the <feed> root element * * @throws JAXBException * if a problem with JAXB occured */ @Override public Feed toObject() throws JAXBException { this.upgradeToLatestVersion(); return (Feed) ImmobiliareItUtils.createUnmarshaller().unmarshal(this.getDocument()); } }