Metacat

/**

 *  Copyright: 2013 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *

 * This program 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 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.index;

import java.io.File;

import java.io.FileNotFoundException;

import java.util.ArrayList;

import java.util.List;

import java.util.Timer;

import org.apache.commons.configuration.ConfigurationException;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.solr.client.solrj.SolrServer;

import org.dataone.configuration.Settings;

import org.dataone.service.exceptions.ServiceFailure;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import org.springframework.context.support.FileSystemXmlApplicationContext;

import com.ibm.icu.util.Calendar;

import edu.ucsb.nceas.metacat.common.SolrServerFactory;

import edu.ucsb.nceas.metacat.common.query.EnabledQueryEngines;

/**

 * The start class of the index.

 * @author tao

 *

 */

public class ApplicationController implements Runnable {

    private static long DEFAULTINTERVAL = 7200000;

    private static String SOLRINDEXES = "solrIndexes";

    private static short FIRST = 0;

    private List<SolrIndex> solrIndexes = null;

    private List<SystemMetadataEventListener> sysmetaListeners = new ArrayList<SystemMetadataEventListener>();

    private static ApplicationContext context = null;

    private String springConfigFileURL = "/index-processor-context.xml";

    private String metacatPropertiesFile = null;

    private static int waitingTime = IndexGenerator.WAITTIME;

    private static int maxAttempts = IndexGenerator.MAXWAITNUMBER;

    private static long period = DEFAULTINTERVAL;

    Log log = LogFactory.getLog(ApplicationController.class);

    /**

     * Constructor

     */

    /*public ApplicationController () throws Exception {

        init();

    }*/

    /**

     * Set the Spring configuration file url and metacat.properties file

     * @param springConfigFile  the path of the Spring configuration file

     * @param metacatPropertyFile  the path of the metacat.properties file

     */

    public ApplicationController(String springConfigFileURL, String metacatPropertiesFile) throws Exception {

        this.springConfigFileURL = springConfigFileURL;

        this.metacatPropertiesFile = metacatPropertiesFile;

        //init();

    }

    /**

     * Loads the metacat.prioerties into D1 Settings utility

     * this gives us access to all metacat properties as well as 

     * overriding any properties as needed. 

     * Note: in the junit test, we are using the test.properties rather than this properties file.

     * 

     * Makes sure shared Hazelcast configuration file location is set

     */

    private void initializeSharedConfiguration() {

        int times = 0;

        boolean foundProperty = false;

        while(true) {

            File metacatProperties = new File(metacatPropertiesFile);

            if(metacatProperties.exists()) {

                foundProperty = true;

                break;

            } else {

                try {

                        Thread.sleep(waitingTime);

                } catch (InterruptedException e) {

                            // TODO Auto-generated catch block

                        e.printStackTrace();

                }

            }

            times++;

            if(times >= maxAttempts) {

                log.error("ApplicationController.initialzeSharedConfiguration - MetacatIndex wait a while and still can't find the metacat.properties file.");

                break;//we still break the while loop and continue. But the properties in the metacat.properties can't be read.

            }

        }

        try {

            Settings.getConfiguration();

            Settings.augmentConfiguration(metacatPropertiesFile);

        } catch (ConfigurationException e) {

            log.error("Could not initialize shared Metacat properties. " + e.getMessage(), e);

        }

        // make sure hazelcast configuration is defined so that

        String hzConfigFileName = Settings.getConfiguration().getString("dataone.hazelcast.configFilePath");

        if (hzConfigFileName == null) {

            // use default metacat hazelcast.xml file in metacat deployment

            hzConfigFileName = 

                    Settings.getConfiguration().getString("application.deployDir") +

                    "/" +

                    Settings.getConfiguration().getString("application.context") + 

                    "/WEB-INF/hazelcast.xml";

            // set it for other parts of the code

            Settings.getConfiguration().setProperty("dataone.hazelcast.configFilePath", hzConfigFileName);

            //set data.hazelcast.location.clientconfig. This property will be used in d1_cn_index_processor module.

            //if we don't set this property, d1_cn_index_processor will use the default location /etc/dataone/storage.

            Settings.getConfiguration().setProperty("dataone.hazelcast.location.clientconfig", hzConfigFileName);

        }

        if(foundProperty) {

            period = Settings.getConfiguration().getLong("index.regenerate.interval");

        }

    }

    /**

     * Initialize the list of the SolrIndex objects from the configuration file.

     * Set the SolrServer implementation using the factory.

     */

    public void initialize() throws Exception {

        context = getContext();

        solrIndexes = (List<SolrIndex>) context.getBean(SOLRINDEXES);

        // use factory to create the correct impl

    	SolrServer solrServer = null;

		try {

			solrServer = SolrServerFactory.createSolrServer();

		} catch (Exception e) {

			log.error("Could not create SolrServer form factory", e);

			throw e;

		}

        // start the SystemMetadata listener[s] (only expect there to be one)

        for (SolrIndex solrIndex: solrIndexes) {

        	// set the solr server to use

			solrIndex.setSolrServer(solrServer);

			// start listening for events

        	SystemMetadataEventListener smel = new SystemMetadataEventListener();

        	smel.setSolrIndex(solrIndex);

        	sysmetaListeners.add(smel);

        	//smel.start();

        }

    }

    /**

     * Get the ApplicaionContext of Spring.

     */

    private ApplicationContext getContext() {

        if (context == null) {

            context = new ClassPathXmlApplicationContext(springConfigFileURL);

        }

        return context;

    }

    /**

     * Get the path of the Spring configuration file.

     * @return the path of the Spring configuration file.

     */

    public String getSpringConfigFile() {

        return this.springConfigFileURL;

    }

    /**

     * Get the list of the solr index.

     * @return the list of the solr index.

     */

    public List<SolrIndex> getSolrIndexes() {

        return this.solrIndexes;

    }

    /**

     * Start to generate indexes for those haven't been indexed in another thread.

     * It will create a timer to run this task periodically. 

     * If the property of "index.regenerate.interval" is less than 0, the thread would NOT run.

     */

    private void startIndexGenerator() {

        if(period > 0) {

            SolrIndex index = solrIndexes.get(FIRST);

            //SystemMetadataEventListener listener = sysmetaListeners.get(FIRST);

            IndexGenerator generator = new IndexGenerator(index);

            //Thread indexThread = new Thread(generator);

            //indexThread.start();

            Timer indexTimer = new Timer();

            //indexTimer.scheduleAtFixedRate(generator, Calendar.getInstance().getTime(), period);

            indexTimer.schedule(generator, 60000, period);

        }

    }

    /**

     * Start the system metadata listener. Prior to call this method, we should call

     * initialize method first.

     * @throws ServiceFailure 

     * @throws FileNotFoundException 

     */

    private void startSysmetaListener() throws FileNotFoundException, ServiceFailure {

        if(sysmetaListeners != null) {

            //only expects one listener.

            for(SystemMetadataEventListener listener : sysmetaListeners) {

                if(listener != null) {

                    listener.start();

                }

            }

        }

    }

    /**

     * It will initialize the shared metacat.properties and the SolrIndex, then start system metadata event listener and 

     *  generate indexes for those haven't been indexed in another thread. This method is for the MetacatIndexServlet.

     *  The reason we put those methods (init, startSysmetaListener, startIndex)in the run (another thread) is that the waiting readiness of the metacat wouldn't 

     *  block the start of the servlet container (e.g., tomcat).

     */

    public void run() {

        initializeSharedConfiguration();

        try {

            boolean isSolrEnabled = true;

            try {

               isSolrEnabled = EnabledQueryEngines.getInstance().isEnabled(EnabledQueryEngines.SOLRENGINE);

            } catch (Exception e) {

                log.error("ApplicationController.run - Metacat-index can't read the enabled query engine list from metacat.properties :"+e.getMessage());

            }

            //if the solr query engine is disabled, we stop here.

            if(!isSolrEnabled) {

                return;

            }

            initialize();

            startSysmetaListener();

            startIndexGenerator();//it will create another thread.

        } catch (Exception e) {

            log.error("Application.run "+e.getMessage());

        }

    }

}