ThreshdConfigFactory.java

/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2006-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 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 org.opennms.netmgt.config;

import java.io.File;
import java.io.FileInputStream;
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;
import org.opennms.core.utils.ThreadCategory;

/**
 * This is the singleton class used to load the configuration for the OpenNMS
 * Thresholding Daemon from the threshd-configuration xml file.
 *
 * A mapping of the configured URLs to the iplist they contain is built at
 * init() time so as to avoid numerous file reads.
 *
 * <strong>Note: </strong>Users of this class should make sure the
 * <em>init()</em> is called before calling any other method to ensure the
 * config is loaded before accessing other convenience methods.
 *
 * @author <a href="mailto:jamesz@opennms.com>James Zuo </a>
 * @author <a href="mailto:mike@opennms.org">Mike Davidson </a>
 * @author <a href="mailto:sowmya@opennms.org">Sowmya Nataraj </a>
 * @author <a href="http://www.opennms.org/">OpenNMS </a>
 */
public final class ThreshdConfigFactory extends ThreshdConfigManager {
    /**
     * The singleton instance of this factory
     */
    private static ThreshdConfigFactory m_singleton = null;

    /**
     * This member is set to true if the configuration file has been loaded.
     */
    private static boolean m_loaded = false;

    /**
     * <p>Constructor for ThreshdConfigFactory.</p>
     *
     * @param stream a {@link java.io.InputStream} object.
     * @param localServer a {@link java.lang.String} object.
     * @param verifyServer a boolean.
     * @throws java.io.IOException if any.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    public ThreshdConfigFactory(InputStream stream, String localServer, boolean verifyServer) throws IOException, MarshalException, ValidationException {
        super(stream, localServer, verifyServer);

    }

    /**
     * Load the config from the default config file and create the singleton
     * instance of this factory.
     *
     * @exception java.io.IOException
     *                Thrown if the specified config file cannot be read
     * @exception org.exolab.castor.xml.MarshalException
     *                Thrown if the file does not conform to the schema.
     * @exception org.exolab.castor.xml.ValidationException
     *                Thrown if the contents do not match the required schema.
     * @throws java.io.IOException 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, MarshalException, ValidationException {
        if (m_loaded) {
            // init already called - return
            // to reload, reload() will need to be called
            return;
        }
        
        OpennmsServerConfigFactory.init();
        boolean verifyServer = OpennmsServerConfigFactory.getInstance().verifyServer();
        String localServer = OpennmsServerConfigFactory.getInstance().getServerName();


        File cfgFile = ConfigFileConstants.getFile(ConfigFileConstants.THRESHD_CONFIG_FILE_NAME);

        ThreadCategory.getInstance(ThreshdConfigFactory.class).debug("init: config file path: " + cfgFile.getPath());

        InputStream stream = null;
        try {
            stream = new FileInputStream(cfgFile);
            m_singleton = new ThreshdConfigFactory(stream, localServer, verifyServer);
            m_loaded = true;
        } finally {
            if (stream != null) {
                IOUtils.closeQuietly(stream);
            }
        }
    }

    /**
     * Reload the config from the default config file
     *
     * @exception java.io.IOException
     *                Thrown if the specified config file cannot be read/loaded
     * @exception org.exolab.castor.xml.MarshalException
     *                Thrown if the file does not conform to the schema.
     * @exception org.exolab.castor.xml.ValidationException
     *                Thrown if the contents do not match the required schema.
     * @throws java.io.IOException if any.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    public static synchronized void reload() throws IOException, MarshalException, ValidationException {
        m_singleton = null;
        m_loaded = false;

        init();
    }

         /**
          * <p>reloadXML</p>
          *
          * @throws java.io.IOException if any.
          * @throws org.exolab.castor.xml.MarshalException if any.
          * @throws org.exolab.castor.xml.ValidationException if any.
          */
         public void reloadXML() throws IOException, MarshalException, ValidationException {
             /* FIXME: THIS IS WAY WRONG! Should only reload the xml not recreate the instance
              otherwise references to the old instance will still linger */
            reload();
        }

        /** {@inheritDoc} */
        protected void saveXML(String xmlString) throws IOException {
            File cfgFile = ConfigFileConstants.getFile(ConfigFileConstants.THRESHD_CONFIG_FILE_NAME);
            Writer fileWriter = new OutputStreamWriter(new FileOutputStream(cfgFile), "UTF-8");
            fileWriter.write(xmlString);
            fileWriter.flush();
            fileWriter.close();
        }
         


    /**
     * Return the singleton instance of this factory.
     *
     * @return The current factory instance.
     * @throws java.lang.IllegalStateException
     *             Thrown if the factory has not yet been initialized.
     */
    public static synchronized ThreshdConfigFactory getInstance() {
        if (!m_loaded)
            throw new IllegalStateException("The factory has not been initialized");

        return m_singleton;
    }
    
    /**
     * <p>setInstance</p>
     *
     * @param configFactory a {@link org.opennms.netmgt.config.ThreshdConfigFactory} object.
     */
    public static void setInstance(ThreshdConfigFactory configFactory) {
    	m_loaded = true;
    	m_singleton = configFactory;
    }
}