Class Produced

dagger-producers/main/java/dagger/producers/Produced.java:47–153

An interface that represents the result of a plain Producer production of type T, or an exception that was thrown during that production. For any type T that can be injected, you can also inject Produced , which enables handling of any exceptions that were thrown dur

 * @since 2.0
 */
@Beta
@CheckReturnValue
public abstract class Produced<T> {
  /**
   * Returns the result of a production.
   *
   * @throws ExecutionException if the production threw an exception
   */
  public abstract T get() throws ExecutionException;

  /**
   * Two {@code Produced} objects compare equal if both are successful with equal values, or both
   * are failed with equal exceptions.
   */
  @Override
  public abstract boolean equals(Object o);

  /** Returns an appropriate hash code to match {@link #equals(Object)}. */
  @Override
  public abstract int hashCode();

  /** Returns a successful {@code Produced}, whose {@link #get} will return the given value. */
  public static <T> Produced<T> successful(@NullableDecl T value) {
    return new Successful<T>(value);
  }

  /**
   * Returns a failed {@code Produced}, whose {@link #get} will throw an
   * {@code ExecutionException} with the given cause.
   */
  public static <T> Produced<T> failed(Throwable throwable) {
    return new Failed<T>(checkNotNull(throwable));
  }

  private static final class Successful<T> extends Produced<T> {
    @NullableDecl private final T value;

    private Successful(@NullableDecl T value) {
      this.value = value;
    }

    @Override
    @NullableDecl
    public T get() {
      return value;
    }

    @Override
    public boolean equals(Object o) {
      if (o == this) {
        return true;
      } else if (o instanceof Successful) {
        Successful<?> that = (Successful<?>) o;
        return Objects.equal(this.value, that.value);
      } else {
        return false;
      }
    }