OptionalLong

AI-generated Key Takeaways

• OptionalLong is a container that may or may not hold a long value.

• It provides methods to check for the presence of a value (isPresent()), retrieve the value if present (getAsLong()), and specify default behavior if the value is absent (orElse(), orElseGet()).

• OptionalLong helps to avoid null checks and potential NullPointerExceptions when working with optional long values.

• It offers functionalities to execute code conditionally based on the presence or absence of the value (ifPresent()).

public final class OptionalLong extends Object

A container object which may or may not contain a long value. If a value is present, isPresent() will return true and getAsLong() will return the value.

Additional methods that depend on the presence or absence of a contained value are provided, such as orElse() (return a default value if value not present) and ifPresent() (execute a block of code if the value is present).

Public Method Summary

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 containing a concise, human-readable description of this object. Returns a non-empty string representation of this object suitable for debugging.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Methods

public static OptionalLong empty ()

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

Returns

• an empty OptionalLong.

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 ==.

Parameters

obj	an object to be tested for equality

Returns

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

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()

public int hashCode ()

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

Returns

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

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

public boolean isPresent ()

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

Returns

• true if there is a value present, otherwise false

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

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

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

public long orElseThrow (Supplier<X> exceptionSupplier)

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

Parameters

exceptionSupplier	The supplier which will return the exception to be thrown

Returns

• the present value

Throws

	if there is no value present
NullPointerException	if no value is present and exceptionSupplier is null
Throwable

public String toString ()

Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:

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

See Writing a useful toString method if you intend implementing your own toString method. 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.

Returns

• the string representation of this instance