public final class OptionalLong
extends Object 

Since:

1.8

• Method Summary

  All Methods

  Modifier and Type	Method	Description
  static OptionalLong	empty ()	Returns an empty OptionalLong instance.
  boolean	equals (Object obj)	Indicates whether some other object is "equal to" this OptionalLong.
  long	getAsLong ()	If a value is present in this OptionalLong, returns the value, otherwise throws NoSuchElementException.
  int	hashCode ()	Returns the hash code value of the present value, if any, or 0 (zero) if no value is present.
  void	ifPresent (LongConsumer consumer)	Have the specified consumer accept the value if a value is present, otherwise do nothing.
  boolean	isPresent ()	Return true if there is a value present, otherwise false.
  static OptionalLong	of (long value)	Return an OptionalLong with the specified value present.
  long	orElse (long other)	Return the value if present, otherwise return other.
  long	orElseGet (LongSupplier other)	Return the value if present, otherwise invoke other and return the result of that invocation.
  <X extends Throwable> long	orElseThrow (Supplier<X> exceptionSupplier)	Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.
  String	toString ()	Returns a string representation of the object.

  • Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

• Method Detail

  • empty

    public static OptionalLong empty()

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

    API Note:

    Though it may be tempting to do so, avoid testing if an object is empty by comparing with == against instances returned by Option.empty(). There is no guarantee that it is a singleton. Instead, use isPresent().

    Returns:

    an empty OptionalLong.

  • of

    public static OptionalLong of(long value)

    Return an OptionalLong with the specified value present.

    Parameters:

    value - the value to be present

    Returns:

    an OptionalLong with the value present

  • getAsLong

    public long getAsLong()

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

    Returns:

    the value held by this OptionalLong

    Throws:

    NoSuchElementException - if there is no value present

    See Also:

    isPresent()

  • isPresent

    public boolean isPresent()

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

    Returns:

    true if there is a value present, otherwise false

  • ifPresent

    public void ifPresent(LongConsumer consumer)

    Have the specified consumer accept the value if a value is present, otherwise do nothing.

    Parameters:

    consumer - block to be executed if a value is present

    Throws:

    NullPointerException - if value is present and consumer is null

  • orElse

    public long orElse(long other)

    Return the value if present, otherwise return other.

    Parameters:

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

    Returns:

    the value, if present, otherwise other

  • orElseGet

    public long orElseGet(LongSupplier other)

    Return the value if present, otherwise invoke other and return the result of that invocation.

    Parameters:

    other - a LongSupplier whose result is returned if no value is present

    Returns:

    the value if present otherwise the result of other.getAsLong()

    Throws:

    NullPointerException - if value is not present and other is null

  • orElseThrow

    public <X extends Throwable> long orElseThrow(Supplier<X> exceptionSupplier)
     throws X

    Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.

    API Note:

    A method reference to the exception constructor with an empty argument list can be used as the supplier. For example, IllegalStateException::new

    Type Parameters:

    X - Type of the exception to be thrown

    Parameters:

    exceptionSupplier - The supplier which will return the exception to be thrown

    Returns:

    the present value

    Throws:

    X - if there is no value present

    NullPointerException - if no value is present and exceptionSupplier is null

    X extends Throwable

  • equals

    public boolean equals(Object obj)

    Indicates whether some other object is "equal to" this OptionalLong. The other object is considered equal if:

    • it is also an OptionalLong and;
    • both instances have no value present or;
    • the present values are "equal to" each other via ==.

    Overrides:

    equals in class Object

    Parameters:

    obj - an object to be tested for equality

    Returns:

    {code true} if the other object is "equal to" this object otherwise false

    See Also:

    Object.hashCode(), HashMap

  • hashCode

    public int hashCode()

    Returns the hash code value of the present value, if any, or 0 (zero) if no value is present.

    Overrides:

    hashCode in class Object

    Returns:

    hash code value of the present value or 0 if no value is present

    See Also:

    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

  • toString

    public String toString()

    Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

    The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

     getClass().getName() + '@' + Integer.toHexString(hashCode())
     

    Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.

    Overrides:

    toString in class Object

    Implementation Requirements:

    If a value is present the result must include its string representation in the result. Empty and present instances must be unambiguously differentiable.

    Returns:

    the string representation of this instance