Class ForwardingCache

android/guava/src/com/google/common/cache/ForwardingCache.java:36–147

A cache which forwards all its method calls to another cache. Subclasses should override one or more methods to modify the behavior of the backing cache as desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. @author Charles Fry @since 10.0

 * @since 10.0
 */
@GwtIncompatible
public abstract class ForwardingCache<K, V> extends ForwardingObject implements Cache<K, V> {

  /** Constructor for use by subclasses. */
  protected ForwardingCache() {}

  @Override
  protected abstract Cache<K, V> delegate();

  /**
   * @since 11.0
   */
  @Override
  public @Nullable V getIfPresent(Object key) {
    return delegate().getIfPresent(key);
  }

  /**
   * @since 11.0
   */
  @Override
  public V get(K key, Callable<? extends V> valueLoader) throws ExecutionException {
    return delegate().get(key, valueLoader);
  }

  /**
   * @since 11.0
   */
  @Override
  /*
   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means class="st">"non-null types," while <?> means class="st">"all types."
   */
  public ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys) {
    return delegate().getAllPresent(keys);
  }

  /**
   * @since 11.0
   */
  @Override
  public void put(K key, V value) {
    delegate().put(key, value);
  }

  /**
   * @since 12.0
   */
  @Override
  public void putAll(Map<? extends K, ? extends V> m) {
    delegate().putAll(m);
  }

  @Override
  public void invalidate(Object key) {
    delegate().invalidate(key);
  }