Subversion Repositories SmartDukaan

/**
 * 
 */
package in.shop2020.creation.util;

import in.shop2020.util.BDBHotBackupTask;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author mandeep
 *
 */
public class BackgroundTaskExecutor implements ServletContextListener {
    private static Log log = LogFactory.getLog(BackgroundTaskExecutor.class);
    private ScheduledExecutorService scheduler;

    @Override
    public void contextInitialized(ServletContextEvent event) {
        log.info("Inside contextInitialized");
        scheduler = Executors.newSingleThreadScheduledExecutor();

        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd HH:MM:ss");
        SimpleDateFormat sdfYYYYMMDD = new SimpleDateFormat("yyyyMMdd");
        long initialDelay = 0;
        long period = 4 * 60 * 60 * 1000; //in milliseconds

        try {
            Calendar calendar = Calendar.getInstance();
            calendar.add(Calendar.DATE, 1);
            initialDelay = sdf.parse(sdfYYYYMMDD.format(calendar.getTime()) + " 15:00:00").getTime() - new Date().getTime();
            initialDelay %= period;
        } catch (ParseException e) {
            log.error("Could not compute initial delay", e);
        }

        scheduler.scheduleAtFixedRate(new BDBHotBackupTask(), initialDelay, period, TimeUnit.MILLISECONDS);
    }

    @Override
    public void contextDestroyed(ServletContextEvent event) {
        log.info("Inside contextDestroyed");
        scheduler.shutdownNow();
    }
}