OpenJDK 1.22 · java.util.OptionalLong · APIdia, the JavaDoc alternative

Modifier and Type	Field and Description
private static final OptionalLong	EMPTY Common instance for `empty()`.
private final boolean	isPresent If true then the value is present, otherwise indicates no value is present
private final long	value

Access	Constructor and Description
private	OptionalLong() Construct an empty instance.
private	OptionalLong(long the long value to describe value) Construct an instance with the described value.

Method Summary

Modifier and Type	Method and Description
public static OptionalLong	Returns: an empty `OptionalLong`. empty() Returns an empty `OptionalLong` instance.
public boolean	Returns: `true` if the other object is "equal to" this object otherwise `false` equals(Object an object to be tested for equality obj) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this `OptionalLong`.
public long	Returns: the value described by this `OptionalLong` getAsLong() If a value is present, returns the value, otherwise throws `NoSuchElementException`.
public int	Returns: hash code value of the present value or `0` if no value is present hashCode() Overrides java.lang.Object.hashCode. Returns the hash code of the value, if present, otherwise `0` (zero) if no value is present.
public void	ifPresent(LongConsumer the action to be performed, if a value is present action) If a value is present, performs the given action with the value, otherwise does nothing.
public void	ifPresentOrElse(LongConsumer the action to be performed, if a value is present action, Runnable the empty-based action to be performed, if no value is present emptyAction) If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
public boolean	Returns: `true` if a value is not present, otherwise `false` isEmpty() If a value is not present, returns `true`, otherwise `false`.
public boolean	Returns: `true` if a value is present, otherwise `false` isPresent() If a value is present, returns `true`, otherwise `false`.
public static OptionalLong	Returns: an `OptionalLong` with the value present of(long the value to describe value) Returns an `OptionalLong` describing the given value.
public long	Returns: the value, if present, otherwise `other` orElse(long the value to be returned, if no value is present other) If a value is present, returns the value, otherwise returns `other`.
public long	Returns: the value, if present, otherwise the result produced by the supplying function orElseGet(LongSupplier the supplying function that produces a value to be returned supplier) If a value is present, returns the value, otherwise returns the result produced by the supplying function.
public long	Returns: the value described by this `OptionalLong` orElseThrow() If a value is present, returns the value, otherwise throws `NoSuchElementException`.
public < Type of the exception to be thrown X extends Throwable> long	Returns: the value, if present orElseThrow(Supplier<? extends X> the supplying function that produces an exception to be thrown exceptionSupplier) If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.
public LongStream	Returns: the optional value as an `LongStream` stream() If a value is present, returns a sequential `LongStream` containing only that value, otherwise returns an empty `LongStream`.
public String	Returns: the string representation of this instance toString() Overrides java.lang.Object.toString. Returns a non-empty string representation of this `OptionalLong` suitable for debugging.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

EMPTY	back to summary
private static final OptionalLong EMPTY Common instance for `empty()`.

isPresent	back to summary
private final boolean isPresent If true then the value is present, otherwise indicates no value is present

value	back to summary
private final long value

OptionalLong	back to summary
private OptionalLong() Construct an empty instance. Implementation Note generally only one empty instance, `OptionalLong#EMPTY`, should exist per VM.

OptionalLong	back to summary
private OptionalLong(long value) Construct an instance with the described value. Parameters value:long the long value to describe

Method Detail

empty back to summary

empty	back to summary
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 `==` or `!=` against instances returned by `OptionalLong.empty()`. There is no guarantee that it is a singleton. Instead, use `isEmpty()` or `isPresent()`. Returns:OptionalLong an empty `OptionalLong`.

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 == or != against instances returned by OptionalLong.empty(). There is no guarantee that it is a singleton. Instead, use isEmpty() or isPresent().

Returns:OptionalLong: an empty OptionalLong.

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.lang.Object.equals. 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:Object an object to be tested for equality Returns:boolean `true` if the other object is "equal to" this object otherwise `false` Annotations @Override

public boolean equals(Object obj)

Overrides java.lang.Object.equals.

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:Object: an object to be tested for equality

Returns:boolean

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

Annotations

@Override

getAsLong back to summary

getAsLong	back to summary
public long getAsLong() If a value is present, returns the value, otherwise throws `NoSuchElementException`. API Note The preferred alternative to this method is `orElseThrow()`. Returns:long the value described by this `OptionalLong` Exceptions NoSuchElementException: if no value is present

public long getAsLong()

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

API Note

The preferred alternative to this method is orElseThrow().

Returns:long

the value described by this OptionalLong

Exceptions

NoSuchElementException:: if no value is present

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Returns the hash code of the value, if present, otherwise `0` (zero) if no value is present. Returns:int hash code value of the present value or `0` if no value is present Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

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

Returns:int

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

Annotations

@Override

ifPresent back to summary

ifPresent	back to summary
public void ifPresent(LongConsumer action) 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 NullPointerException: if value is present and the given action is `null`

public void ifPresent(LongConsumer action)

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

NullPointerException:: if value is present and the given action is null

ifPresentOrElse back to summary

ifPresentOrElse	back to summary
public void ifPresentOrElse(LongConsumer action, Runnable emptyAction) 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 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`. Since 9

public void ifPresentOrElse(LongConsumer action, Runnable emptyAction)

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

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.

Since

isEmpty back to summary

isEmpty	back to summary
public boolean isEmpty() If a value is not present, returns `true`, otherwise `false`. Returns:boolean `true` if a value is not present, otherwise `false` Since 11

public boolean isEmpty()

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

Returns:boolean: true if a value is not present, otherwise false
Since: 11

isPresent back to summary

isPresent	back to summary
public boolean isPresent() If a value is present, returns `true`, otherwise `false`. Returns:boolean `true` if a value is present, otherwise `false`

public boolean isPresent()

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

Returns:boolean: true if a value is present, otherwise false

of back to summary

of	back to summary
public static OptionalLong of(long value) Returns an `OptionalLong` describing the given value. Parameters value:long the value to describe Returns:OptionalLong an `OptionalLong` with the value present

public static OptionalLong of(long value)

Returns an OptionalLong describing the given value.

Parameters

value:long: the value to describe

Returns:OptionalLong

an OptionalLong with the value present

orElse back to summary

orElse	back to summary
public long orElse(long other) If a value is present, returns the value, otherwise returns `other`. Parameters other:long the value to be returned, if no value is present Returns:long the value, if present, otherwise `other`

public long orElse(long other)

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

Parameters

other:long: the value to be returned, if no value is present

Returns:long

the value, if present, otherwise other

orElseGet back to summary

orElseGet	back to summary
public long orElseGet(LongSupplier supplier) 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 Returns:long the value, if present, otherwise the result produced by the supplying function Exceptions NullPointerException: if no value is present and the supplying function is `null`

public long orElseGet(LongSupplier supplier)

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

Returns:long

the value, if present, otherwise the result produced by the supplying function

Exceptions

NullPointerException:: if no value is present and the supplying function is null

orElseThrow back to summary

orElseThrow	back to summary
public long orElseThrow() If a value is present, returns the value, otherwise throws `NoSuchElementException`. Returns:long the value described by this `OptionalLong` Exceptions NoSuchElementException: if no value is present Since 10

public long orElseThrow()

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

Returns:long

the value described by this OptionalLong

Exceptions

NoSuchElementException:: if no value is present

Since

orElseThrow back to summary

orElseThrow	back to summary
public <X extends Throwable> long orElseThrow(Supplier<? extends X> exceptionSupplier) throws Supplier-:X If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function. API Note A method reference to the exception constructor with an empty argument list can be used as the supplier. For example, `IllegalStateException::new` Parameters <X> Type of the exception to be thrown exceptionSupplier:Supplier<? extends X> the supplying function that produces an exception to be thrown Returns:long the value, if present Exceptions Supplier-:X: if no value is present NullPointerException: if no value is present and the exception supplying function is `null`

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

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

API Note

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

Parameters

<X>: Type of the exception to be thrown
exceptionSupplier:Supplier<? extends X>: the supplying function that produces an exception to be thrown

Returns:long

the value, if present

Exceptions

Supplier-:X:: if no value is present
NullPointerException:: if no value is present and the exception supplying function is null

stream back to summary

stream	back to summary
public LongStream stream() If a value is present, returns a sequential `LongStream` containing only that value, otherwise returns an empty `LongStream`. API Note This method can be used to transform a `Stream` of optional longs to an `LongStream` of present longs: `Stream<OptionalLong> os = .. LongStream s = os.flatMapToLong(OptionalLong::stream)` Returns:LongStream the optional value as an `LongStream` Since 9

public LongStream stream()

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

API Note

This method can be used to transform a Stream of optional longs to an LongStream of present longs:

Stream<OptionalLong> os = ..
    LongStream s = os.flatMapToLong(OptionalLong::stream)

Returns:LongStream: the optional value as an LongStream
Since: 9

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. 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. Implementation Specification If a value is present the result must include its string representation in the result. Empty and present `OptionalLong`s must be unambiguously differentiable. Returns:String the string representation of this instance Annotations @Override

public String toString()

Overrides java.lang.Object.toString.

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.

Implementation Specification

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

Returns:String

the string representation of this instance

Annotations

@Override

public final Class OptionalLong

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail