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.examples; import java.io.File; import java.io.IOException; import java.io.InputStream; import javax.xml.bind.JAXBException; import javax.xml.parsers.ParserConfigurationException; import org.apache.commons.lang3.StringUtils; import org.apache.log4j.PropertyConfigurator; import org.openestate.io.immobiliare_it.ImmobiliareItDocument; import org.openestate.io.immobiliare_it.ImmobiliareItUtils; import org.openestate.io.immobiliare_it.xml.Feed; import org.openestate.io.immobiliare_it.xml.Feed.Properties.Property; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.xml.sax.SAXException; /** * Example for reading XML files for * <a href="http://immobiliare.it">immobiliare.it</a>. * <p> * This example illustrates how to read XML files for * <a href="http://immobiliare.it">immobiliare.it</a>. * * @since 1.0 * @author Andreas Rudolph */ public class ImmobiliareItReadingExample { private final static Logger LOGGER = LoggerFactory.getLogger(ImmobiliareItReadingExample.class); private final static String PACKAGE = "/org/openestate/io/examples"; /** * Start the example application. * * @param args * command line arguments */ public static void main(String[] args) { // init logging PropertyConfigurator .configure(ImmobiliareItReadingExample.class.getResource(PACKAGE + "/log4j.properties")); // read example files, if no files were specified as command line arguments if (args.length < 1) { try { read(ImmobiliareItReadingExample.class.getResourceAsStream(PACKAGE + "/immobiliare_it.xml")); } catch (Exception ex) { LOGGER.error("Can't read example file!"); LOGGER.error("> " + ex.getLocalizedMessage(), ex); System.exit(2); } } // read files, that were specified as command line arguments else { for (String arg : args) { try { read(new File(arg)); } catch (Exception ex) { LOGGER.error("Can't read file '" + arg + "'!"); LOGGER.error("> " + ex.getLocalizedMessage(), ex); System.exit(2); } } } } /** * Read a {@link File} into an {@link ImmobiliareItDocument} and print some * of its content to console. * * @param xmlFile * the file to read * * @throws SAXException * if the file is not readable by the XML parser * * @throws IOException * if the file is not readable * * @throws ParserConfigurationException * if the XML parser is improperly configured * * @throws JAXBException * if XML conversion into Java objects failed */ protected static void read(File xmlFile) throws SAXException, IOException, ParserConfigurationException, JAXBException { LOGGER.info("process file: " + xmlFile.getAbsolutePath()); if (!xmlFile.isFile()) { LOGGER.warn("> provided file is invalid"); return; } ImmobiliareItDocument doc = ImmobiliareItUtils.createDocument(xmlFile); if (doc == null) { LOGGER.warn("> provided XML is not supported"); } else { printToConsole(doc); } } /** * Read a {@link InputStream} into an {@link ImmobiliareItDocument} and print * some of its content to console. * * @param xmlInputStream * the input stream to read * * @throws SAXException * if the file is not readable by the XML parser * * @throws IOException * if the file is not readable * * @throws ParserConfigurationException * if the XML parser is improperly configured * * @throws JAXBException * if XML conversion into Java objects failed */ protected static void read(InputStream xmlInputStream) throws SAXException, IOException, ParserConfigurationException, JAXBException { LOGGER.info("process example file"); ImmobiliareItDocument doc = ImmobiliareItUtils.createDocument(xmlInputStream); if (doc == null) { LOGGER.warn("> provided XML is not supported"); } else { printToConsole(doc); } } /** * Print some content of an {@link ImmobiliareItDocument} to console. * * @param doc * the document to process * * @throws JAXBException * if XML conversion into Java objects failed */ protected static void printToConsole(ImmobiliareItDocument doc) throws JAXBException { LOGGER.info("> process document in version " + doc.getDocumentVersion()); Feed feed = doc.toObject(); // process properties if (feed.getProperties() != null) { for (Property object : feed.getProperties().getProperty()) { // get object nr String objectNr = StringUtils.trimToNull(object.getUniqueId()); if (objectNr == null) objectNr = "???"; // get object description String objectInfo = (object.getFeatures() != null && !object.getFeatures().getDescription().isEmpty()) ? StringUtils.trimToNull(object.getFeatures().getDescription().get(0).getValue()) : null; if (objectInfo == null) objectInfo = "???"; // print object informations to console LOGGER.info("> found object " + "'" + objectNr + "': " + objectInfo); } } } }