public
final
class
OptionalLong
extends Object
| java.lang.Object | |
| ↳ | java.util.OptionalLong |
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 methods | |
|---|---|
static
OptionalLong
|
empty()
Returns an empty |
boolean
|
equals(Object obj)
Indicates whether some other object is "equal to" this OptionalLong. |
long
|
getAsLong()
If a value is present in this |
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 |
static
OptionalLong
|
of(long value)
Return an |
long
|
orElse(long other)
Return the value if present, otherwise return |
long
|
orElseGet(LongSupplier other)
Return the value if present, otherwise invoke |
<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. Returns a non-empty string representation of this object suitable for debugging. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
OptionalLong empty ()
Returns an empty OptionalLong instance. No value is present for this
OptionalLong.
Developers
== against instances returned by
Option.empty(). There is no guarantee that it is a singleton.
Instead, use isPresent().| Returns | |
|---|---|
OptionalLong |
an empty OptionalLong.
|
boolean equals (Object obj)
Indicates whether some other object is "equal to" this OptionalLong. The other object is considered equal if:
OptionalLong and;
==.
| Parameters | |
|---|---|
obj |
Object:
an object to be tested for equality |
| Returns | |
|---|---|
boolean |
{code true} if the other object is "equal to" this object
otherwise false
|
long getAsLong ()
If a value is present in this OptionalLong, returns the value,
otherwise throws NoSuchElementException.
| Returns | |
|---|---|
long |
the value held by this OptionalLong |
| Throws | |
|---|---|
NoSuchElementException |
if there is no value present |
See also:
int hashCode ()
Returns the hash code value of the present value, if any, or 0 (zero) if no value is present.
| Returns | |
|---|---|
int |
hash code value of the present value or 0 if no value is present |
void ifPresent (LongConsumer consumer)
Have the specified consumer accept the value if a value is present, otherwise do nothing.
| Parameters | |
|---|---|
consumer |
LongConsumer:
block to be executed if a value is present |
| Throws | |
|---|---|
NullPointerException |
if value is present and consumer is
null
|
boolean isPresent ()
Return true if there is a value present, otherwise false.
| Returns | |
|---|---|
boolean |
true if there is a value present, otherwise false
|
OptionalLong of (long value)
Return an OptionalLong with the specified value present.
| Parameters | |
|---|---|
value |
long:
the value to be present |
| Returns | |
|---|---|
OptionalLong |
an OptionalLong with the value present
|
long orElse (long other)
Return the value if present, otherwise return other.
| Parameters | |
|---|---|
other |
long:
the value to be returned if there is no value present |
| Returns | |
|---|---|
long |
the value, if present, otherwise other
|
long orElseGet (LongSupplier other)
Return the value if present, otherwise invoke other and return
the result of that invocation.
| Parameters | |
|---|---|
other |
LongSupplier:
a LongSupplier whose result is returned if no value
is present |
| Returns | |
|---|---|
long |
the value if present otherwise the result of other.getAsLong() |
| Throws | |
|---|---|
NullPointerException |
if value is not present and other is
null
|
long orElseThrow (Supplier<X> exceptionSupplier)
Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.
IllegalStateException::new| Parameters | |
|---|---|
exceptionSupplier |
Supplier:
The supplier which will return the exception to
be thrown |
| Returns | |
|---|---|
long |
the present value |
| Throws | |
|---|---|
|
if there is no value present |
NullPointerException |
if no value is present and
exceptionSupplier is null
|
Throwable |
|
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:
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.getClass().getName() + '@' + Integer.toHexString(hashCode())
| Returns | |
|---|---|
String |
the string representation of this instance |