Added in API level 24

OptionalLong

class OptionalLong
kotlin.Any
   ↳ java.util.OptionalLong

A container object which may or may not contain a long value. If a value is present, isPresent() returns true. If no value is present, the object is considered empty and isPresent() returns false.

Additional methods that depend on the presence or absence of a contained value are provided, such as orElse() (returns a default value if no value is present) and ifPresent() (performs an action if a value is present).

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

Summary

Public methods
static OptionalLong!

Returns an empty OptionalLong instance.

Boolean
equals(other: Any?)

Indicates whether some other object is "equal to" this OptionalLong.

Long

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

Int

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

Unit

If a value is present, performs the given action with the value, otherwise does nothing.

Unit
ifPresentOrElse(action: LongConsumer!, emptyAction: Runnable!)

If a value is present, performs the given action with the value, otherwise performs the given empty-based action.

Boolean

If a value is not present, returns true, otherwise false.

Boolean

If a value is present, returns true, otherwise false.

static OptionalLong!
of(value: Long)

Returns an OptionalLong describing the given value.

Long
orElse(other: Long)

If a value is present, returns the value, otherwise returns other.

Long
orElseGet(supplier: LongSupplier!)

If a value is present, returns the value, otherwise returns the result produced by the supplying function.

Long

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

Long
orElseThrow(exceptionSupplier: Supplier<out X>!)

If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.

LongStream!

If a value is present, returns a sequential LongStream containing only that value, otherwise returns an empty LongStream.

String

Returns a non-empty string representation of this OptionalLong suitable for debugging.

Public methods

empty

Added in API level 24
static fun empty(): OptionalLong!

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

Return
OptionalLong! an empty OptionalLong.

equals

Added in API level 24
fun equals(other: Any?): Boolean

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
Return
Boolean true if the other object is "equal to" this object otherwise false

getAsLong

Added in API level 24
fun getAsLong(): Long

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

Return
Long the value described by this OptionalLong
Exceptions
java.util.NoSuchElementException if no value is present

hashCode

Added in API level 24
fun hashCode(): Int

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

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

ifPresent

Added in API level 24
fun ifPresent(action: LongConsumer!): Unit

If a value is present, performs the given action with the value, otherwise does nothing.

Parameters
action LongConsumer!: the action to be performed, if a value is present
Exceptions
java.lang.NullPointerException if value is present and the given action is null

ifPresentOrElse

Added in API level 33
fun ifPresentOrElse(
    action: LongConsumer!,
    emptyAction: Runnable!
): Unit

If a value is present, performs the given action with the value, otherwise performs the given empty-based action.

Parameters
action LongConsumer!: the action to be performed, if a value is present
emptyAction Runnable!: the empty-based action to be performed, if no value is present
Exceptions
java.lang.NullPointerException if a value is present and the given action is null, or no value is present and the given empty-based action is null.

isEmpty

Added in API level 33
fun isEmpty(): Boolean

If a value is not present, returns true, otherwise false.

Return
Boolean true if a value is not present, otherwise false

isPresent

Added in API level 24
fun isPresent(): Boolean

If a value is present, returns true, otherwise false.

Return
Boolean true if a value is present, otherwise false

of

Added in API level 24
static fun of(value: Long): OptionalLong!

Returns an OptionalLong describing the given value.

Parameters
value Long: the value to describe
Return
OptionalLong! an OptionalLong with the value present

orElse

Added in API level 24
fun orElse(other: Long): Long

If a value is present, returns the value, otherwise returns other.

Parameters
other Long: the value to be returned, if no value is present
Return
Long the value, if present, otherwise other

orElseGet

Added in API level 24
fun orElseGet(supplier: LongSupplier!): Long

If a value is present, returns the value, otherwise returns the result produced by the supplying function.

Parameters
supplier LongSupplier!: the supplying function that produces a value to be returned
Return
Long the value, if present, otherwise the result produced by the supplying function
Exceptions
java.lang.NullPointerException if no value is present and the supplying function is null

orElseThrow

Added in API level 33
fun orElseThrow(): Long

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

Return
Long the value described by this OptionalLong
Exceptions
java.util.NoSuchElementException if no value is present

orElseThrow

Added in API level 24
fun <X : Throwable!> orElseThrow(exceptionSupplier: Supplier<out X>!): Long

If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.

Parameters
<X> Type of the exception to be thrown
exceptionSupplier Supplier<out X>!: the supplying function that produces an exception to be thrown
Return
Long the value, if present
Exceptions
X if no value is present
java.lang.NullPointerException if no value is present and the exception supplying function is null

stream

Added in API level 33
fun stream(): LongStream!

If a value is present, returns a sequential LongStream containing only that value, otherwise returns an empty LongStream.

Return
LongStream! the optional value as an LongStream

toString

Added in API level 24
fun toString(): String

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

Return
String the string representation of this instance