Class ImmediateFuture

output/java_guava/1.4.16/ImmediateFuture.java:33–163

Implementations of Futures.immediate .

@GwtCompatible(emulated = true)
abstract class ImmediateFuture<V> implements ListenableFuture<V> {
  private static final Logger log = Logger.getLogger(ImmediateFuture.class.getName());

  @Override
  public void addListener(Runnable listener, Executor executor) {
    checkNotNull(listener, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");
    try {
      executor.execute(listener);
    } catch (RuntimeException e) {
      // ListenableFuture's contract is that it will not throw unchecked exceptions, so log the bad
      // runnable and/or executor and swallow it.
      log.log(
          Level.SEVERE,
          "RuntimeException while executing runnable " + listener + " with executor "
            + executor,
          e);
    }
  }

  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    return false;
  }

  @Override
  public abstract V get() throws ExecutionException;

  @Override
  public V get(long timeout, TimeUnit unit) throws ExecutionException {
    checkNotNull(unit);
    return get();
  }

  @Override
  public boolean isCancelled() {
    return false;
  }

  @Override
  public boolean isDone() {
    return true;
  }


  static class ImmediateSuccessfulFuture<V> extends ImmediateFuture<V> {
    static final ImmediateSuccessfulFuture<Object> NULL = new ImmediateSuccessfulFuture<Object>(null);

    @Nullable
    private final V value;

    ImmediateSuccessfulFuture(@Nullable V value) {
      this.value = value;
    }

    // TODO(lukes): Consider throwing InterruptedException when appropriate.