Java tutorial
/******************************************************************************* * This file is part of OpenNMS(R). * * Copyright (C) 2012 The OpenNMS Group, Inc. * OpenNMS(R) is Copyright (C) 1999-2012 The OpenNMS Group, Inc. * * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc. * * OpenNMS(R) is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation, either version 3 of the License, * or (at your option) any later version. * * OpenNMS(R) is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with OpenNMS(R). If not, see: * http://www.gnu.org/licenses/ * * For more information contact: * OpenNMS(R) Licensing <license@opennms.org> * http://www.opennms.org/ * http://www.opennms.com/ *******************************************************************************/ package com.netxforge.oss2.config; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.io.Writer; import org.apache.commons.io.IOUtils; import org.exolab.castor.xml.MarshalException; import org.exolab.castor.xml.ValidationException; import org.opennms.core.utils.ConfigFileConstants; /** * <p>NotifdConfigFactory class.</p> * * @author ranger * @version $Id: $ */ public class NotifdConfigFactory extends NotifdConfigManager { /** * Singleton instance */ private static NotifdConfigFactory instance; /** * Boolean indicating if the init() method has been called */ private static boolean initialized = false; /** * */ private File m_notifdConfFile; /** * */ private long m_lastModified; /** * */ private NotifdConfigFactory() { } /** * <p>Getter for the field <code>instance</code>.</p> * * @return a {@link org.opennms.netmgt.config.NotifdConfigFactory} object. */ static synchronized public NotifdConfigFactory getInstance() { if (!initialized) throw new IllegalStateException("init() not called."); return instance; } /** * <p>init</p> * * @throws java.io.IOException if any. * @throws java.io.FileNotFoundException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. */ public static synchronized void init() throws IOException, FileNotFoundException, MarshalException, ValidationException { if (!initialized) { instance = new NotifdConfigFactory(); instance.reload(); initialized = true; } } /** * <p>reload</p> * * @throws java.io.IOException if any. * @throws java.io.FileNotFoundException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. */ public synchronized void reload() throws IOException, FileNotFoundException, MarshalException, ValidationException { m_notifdConfFile = ConfigFileConstants.getFile(ConfigFileConstants.NOTIFD_CONFIG_FILE_NAME); InputStream configIn = null; try { configIn = new FileInputStream(m_notifdConfFile); m_lastModified = m_notifdConfFile.lastModified(); parseXml(configIn); } finally { if (configIn != null) { IOUtils.closeQuietly(configIn); } } } /** * Gets a nicely formatted string for the Web UI to display * * @return On, Off, or Unknown depending on status * * TODO: Pull up into base class but keep this reference for the * webapp until singleton is removed. * @throws java.io.IOException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. */ public static String getPrettyStatus() throws IOException, MarshalException, ValidationException { if (!initialized) return "Unknown"; String status = "Unknown"; status = NotifdConfigFactory.getInstance().getNotificationStatus(); if (status.equals("on")) status = "On"; else if (status.equals("off")) status = "Off"; return status; } /** {@inheritDoc} */ @Override protected void saveXml(String xml) throws IOException { if (xml != null) { Writer fileWriter = new OutputStreamWriter(new FileOutputStream(m_notifdConfFile), "UTF-8"); fileWriter.write(xml); fileWriter.flush(); fileWriter.close(); } } /** * <p>update</p> * * @throws java.io.IOException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. */ @Override protected synchronized void update() throws IOException, MarshalException, ValidationException { if (m_lastModified != m_notifdConfFile.lastModified()) { NotifdConfigFactory.getInstance().reload(); } } }