/** {@inheritDoc} */
  @SuppressWarnings("deprecation")
  @Override
  public void start() throws IgniteException {
    if (sesFactory == null && F.isEmpty(hibernateCfgPath))
      throw new IgniteException(
          "Either session factory or Hibernate configuration file is required by "
              + getClass().getSimpleName()
              + '.');

    if (!F.isEmpty(hibernateCfgPath)) {
      if (sesFactory == null) {
        try {
          URL url = new URL(hibernateCfgPath);

          sesFactory = new Configuration().configure(url).buildSessionFactory();
        } catch (MalformedURLException ignored) {
          // No-op.
        }

        if (sesFactory == null) {
          File cfgFile = new File(hibernateCfgPath);

          if (cfgFile.exists())
            sesFactory = new Configuration().configure(cfgFile).buildSessionFactory();
        }

        if (sesFactory == null)
          sesFactory = new Configuration().configure(hibernateCfgPath).buildSessionFactory();

        if (sesFactory == null)
          throw new IgniteException(
              "Failed to resolve Hibernate configuration file: " + hibernateCfgPath);

        closeSesOnStop = true;
      } else
        U.warn(
            log,
            "Hibernate configuration file configured in "
                + getClass().getSimpleName()
                + " will be ignored (session factory is already set).");
    }
  }
  /**
   * Initializes store.
   *
   * @throws GridException If failed to initialize.
   */
  private void init() throws GridException {
    if (initGuard.compareAndSet(false, true)) {
      if (log.isDebugEnabled()) log.debug("Initializing cache store.");

      try {
        if (sesFactory != null)
          // Session factory has been provided - nothing to do.
          return;

        if (!F.isEmpty(hibernateCfgPath)) {
          try {
            URL url = new URL(hibernateCfgPath);

            sesFactory = new Configuration().configure(url).buildSessionFactory();

            if (log.isDebugEnabled()) log.debug("Configured session factory using URL: " + url);

            // Session factory has been successfully initialized.
            return;
          } catch (MalformedURLException e) {
            if (log.isDebugEnabled())
              log.debug("Caught malformed URL exception: " + e.getMessage());
          }

          // Provided path is not a valid URL. File?
          File cfgFile = new File(hibernateCfgPath);

          if (cfgFile.exists()) {
            sesFactory = new Configuration().configure(cfgFile).buildSessionFactory();

            if (log.isDebugEnabled())
              log.debug("Configured session factory using file: " + hibernateCfgPath);

            // Session factory has been successfully initialized.
            return;
          }

          // Provided path is not a file. Classpath resource?
          sesFactory = new Configuration().configure(hibernateCfgPath).buildSessionFactory();

          if (log.isDebugEnabled())
            log.debug("Configured session factory using classpath resource: " + hibernateCfgPath);
        } else {
          if (hibernateProps == null) {
            U.warn(
                log, "No Hibernate configuration has been provided for store (will use default).");

            hibernateProps = new Properties();

            hibernateProps.setProperty("hibernate.connection.url", DFLT_CONN_URL);
            hibernateProps.setProperty("hibernate.show_sql", DFLT_SHOW_SQL);
            hibernateProps.setProperty("hibernate.hbm2ddl.auto", DFLT_HBM2DDL_AUTO);
          }

          Configuration cfg = new Configuration();

          cfg.setProperties(hibernateProps);

          assert resourceAvailable(MAPPING_RESOURCE);

          cfg.addResource(MAPPING_RESOURCE);

          sesFactory = cfg.buildSessionFactory();

          if (log.isDebugEnabled())
            log.debug("Configured session factory using properties: " + hibernateProps);
        }
      } catch (HibernateException e) {
        throw new GridException("Failed to initialize store.", e);
      } finally {
        initLatch.countDown();
      }
    } else if (initLatch.getCount() > 0) U.await(initLatch);

    if (sesFactory == null) throw new GridException("Cache store was not properly initialized.");
  }