Method Detail

• empty

  public static <T> Optional<T> empty()

  Returns an empty Optional instance. No value is present for this Optional.

• of

  public static <T> Optional<T> of(@NonNull
                                   T value)

  Returns an Optional with the specified present non-null value.

  Parameters:

  value - the value to be present, which must be non-null

  Returns:

  an Optional with the value present

• ofNullable

  public static <T> Optional<T> ofNullable(T value)

  Returns an Optional describing the specified value, if non-null, otherwise returns an empty Optional.

  Parameters:

  value - the possibly-null value to describe

  Returns:

  an Optional with a present value if the specified value is non-null, otherwise an empty Optional

• get

  public T get()

  If a value is present in this Optional, returns the value, otherwise throws NoSuchElementException.

  Returns:

  the non-null value held by this Optional

  Throws:

  NoSuchElementException - - if there is no value present

• isPresent

  public boolean isPresent()

  Return true if there is a value present, otherwise false.

  Returns:

  true if there is a value present, otherwise false

• orElse

  public T orElse(T other)

  Return the value if present, otherwise return other.

  Parameters:

  other - the value to be returned if there is no value present, may be null

  Returns:

• toString

  public String toString()

  Overrides:

  toString in class Object