loading.gif...

   *
   * <p>No observable state associated with this cache is modified until loading completes.
   *
   * @throws ExecutionException if a checked exception was thrown while loading the value
   * @throws UncheckedExecutionException if an unchecked exception was thrown while loading the
   *     value
   * @throws ExecutionError if an error was thrown while loading the value
   * @since 11.0
   */

 *       <ul>
 *         <li>After successfully loading an entry {@code missCount} and {@code loadSuccessCount}
 *             are incremented, and the total loading time, in nanoseconds, is added to {@code
 *             totalLoadTime}.
 *         <li>When an exception is thrown while loading an entry, {@code missCount} and {@code
 *             loadExceptionCount} are incremented, and the total loading time, in nanoseconds, is

(A SQL separator is semicolon ";")

take-finally-*.sql:
SQL statements for check loaded data (or DDL after data loading)
You should write your own SQL statements in this file.
(basically same specifications as replace-schema.sql)

The "data" directory is for data loading like this:
/- - - - - - - - - - - - - - - - - - - -
playsql
  |-data
     |-common
     |  |-xls
     |     |-10-master.xls

   *
   * <p>No observable state associated with this cache is modified until loading completes.
   *
   * @throws ExecutionException if a checked exception was thrown while loading the value
   * @throws UncheckedExecutionException if an unchecked exception was thrown while loading the
   *     value
   * @throws ExecutionError if an error was thrown while loading the value
   * @since 11.0
   */

  /**
   * Returns a cache loader that uses {@code function} to load keys, without supporting either
   * reloading or bulk loading. This allows creating a cache loader using a lambda expression.
   *
   * <p>The returned object is serializable if {@code function} is serializable.
   *
   * @param function the function to be used for loading values; must never return {@code null}

/**
 * An entry in a reference map.
 *
 * <p>Entries in the map can be in the following states:
 *
 * <p>Valid:
 *
 * <ul>
 *   <li>Live: valid key/value are set
 *   <li>Loading: loading is pending
 * </ul>
 *
 * <p>Invalid:
 *
 * <ul>
 *   <li>Expired: time expired (key/value may still be set)
 *   <li>Collected: key/value was partially collected, but not yet cleaned up

 * [Glide](https://github.com/bumptech/glide): An image loading and caching library for Android focused on smooth scrolling.
 * [GoogleAppEngineOkHttp](https://github.com/apkelly/GoogleAppEngineOkHttp): An OkHttp Call that works on Google App Engine.
 * [Hunter](https://github.com/Leaking/Hunter): Configure all OkHttpClients centrally.

   * segments, each governed by its own write lock. The segment lock is taken once for each explicit
   * write, and twice for each cache loading computation (once prior to loading the new value, and
   * once after loading completes). Much internal cache management is performed at the segment
   * granularity. For example, access queues and write queues are kept per segment when they are

      return this;
    }

    public void setLoading(boolean loading) {
      this.loading = loading;
    }

    @Override
    public boolean isLoading() {
      return loading;
    }

    @Override
    public boolean isActive() {
      return !loading;
    }

    @Override
    public V waitForValue() {
      return get();
    }