Movatterモバイル変換

Class OptionalInt

java.lang.Object
- java.util.OptionalInt

```
public final classOptionalIntextendsObject
```
A container object which may or may not contain anint value. If a value is present,isPresent() returnstrue. If no value is present, the object is consideredempty andisPresent() returnsfalse.
Additional methods that depend on the presence or absence of a contained value are provided, such asorElse() (returns a default value if no value is present) andifPresent() (performs an action if a value is present).
This is avalue-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances ofOptionalInt may have unpredictable results and should be avoided.
API Note:
OptionalInt is primarily intended for use as a method return type where there is a clear need to represent "no result." A variable whose type isOptionalInt should never itself benull; it should always point to anOptionalInt instance.
Since:
1.8

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`staticOptionalInt`	`empty()`	Returns an empty`OptionalInt` instance.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this`OptionalInt`.
`int`	`getAsInt()`	If a value is present, returns the value, otherwise throws`NoSuchElementException`.
`int`	`hashCode()`	Returns the hash code of the value, if present, otherwise`0` (zero) if no value is present.
`void`	`ifPresent(IntConsumer action)`	If a value is present, performs the given action with the value, otherwise does nothing.
`void`	`ifPresentOrElse(IntConsumer action,Runnable emptyAction)`	If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
`boolean`	`isEmpty()`	If a value is not present, returns`true`, otherwise`false`.
`boolean`	`isPresent()`	If a value is present, returns`true`, otherwise`false`.
`staticOptionalInt`	`of(int value)`	Returns an`OptionalInt` describing the given value.
`int`	`orElse(int other)`	If a value is present, returns the value, otherwise returns`other`.
`int`	`orElseGet(IntSupplier supplier)`	If a value is present, returns the value, otherwise returns the result produced by the supplying function.
`int`	`orElseThrow()`	If a value is present, returns the value, otherwise throws`NoSuchElementException`.
`<X extendsThrowable> int`	`orElseThrow(Supplier<? extends X> exceptionSupplier)`	If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.
`IntStream`	`stream()`	If a value is present, returns a sequential`IntStream` containing only that value, otherwise returns an empty`IntStream`.
`String`	`toString()`	Returns a non-empty string representation of this`OptionalInt` suitable for debugging.

Methods declared in class java.lang.Object
clone,finalize,getClass,notify,notifyAll,wait,wait,wait

- Method Detail
  - empty
```
public static OptionalInt empty()
```
    Returns an emptyOptionalInt instance. No value is present for thisOptionalInt.
    API Note:
    Though it may be tempting to do so, avoid testing if an object is empty by comparing with== against instances returned byOptionalInt.empty(). There is no guarantee that it is a singleton. Instead, useisPresent().
    Returns:
    an emptyOptionalInt
  - of
```
public static OptionalInt of(int value)
```
    Returns anOptionalInt describing the given value.
    Parameters:
    value - the value to describe
    Returns:
    anOptionalInt with the value present
  - getAsInt
```
public int getAsInt()
```
    If a value is present, returns the value, otherwise throwsNoSuchElementException.
    API Note:
    The preferred alternative to this method isorElseThrow().
    Returns:
    the value described by thisOptionalInt
    Throws:
    NoSuchElementException - if no value is present
  - isPresent
```
public boolean isPresent()
```
    If a value is present, returnstrue, otherwisefalse.
    Returns:
    true if a value is present, otherwisefalse
  - isEmpty
```
public boolean isEmpty()
```
    If a value is not present, returnstrue, otherwisefalse.
    Returns:
    true if a value is not present, otherwisefalse
    Since:
    11
  - ifPresent
```
public void ifPresent(IntConsumer action)
```
    If a value is present, performs the given action with the value, otherwise does nothing.
    Parameters:
    action - the action to be performed, if a value is present
    Throws:
    NullPointerException - if value is present and the given action isnull
  - ifPresentOrElse
```
public void ifPresentOrElse(IntConsumer action,Runnable emptyAction)
```
    If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
    Parameters:
    action - the action to be performed, if a value is present
    emptyAction - the empty-based action to be performed, if no value is present
    Throws:
    NullPointerException - if a value is present and the given action isnull, or no value is present and the given empty-based action isnull.
    Since:
    9
  - stream
```
public IntStream stream()
```
    If a value is present, returns a sequentialIntStream containing only that value, otherwise returns an emptyIntStream.
    API Note:
    This method can be used to transform aStream of optional integers to anIntStream of present integers:
    Stream<OptionalInt> os = .. IntStream s = os.flatMapToInt(OptionalInt::stream)
    Returns:
    the optional value as anIntStream
    Since:
    9
  - orElse
```
public int orElse(int other)
```
    If a value is present, returns the value, otherwise returnsother.
    Parameters:
    other - the value to be returned, if no value is present
    Returns:
    the value, if present, otherwiseother
  - orElseGet
```
public int orElseGet(IntSupplier supplier)
```
    If a value is present, returns the value, otherwise returns the result produced by the supplying function.
    Parameters:
    supplier - the supplying function that produces a value to be returned
    Returns:
    the value, if present, otherwise the result produced by the supplying function
    Throws:
    NullPointerException - if no value is present and the supplying function isnull
  - orElseThrow
```
public int orElseThrow()
```
    If a value is present, returns the value, otherwise throwsNoSuchElementException.
    Returns:
    the value described by thisOptionalInt
    Throws:
    NoSuchElementException - if no value is present
    Since:
    10
  - orElseThrow
```
public <X extendsThrowable> int orElseThrow(Supplier<? extends X> exceptionSupplier)                                      throws 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
    Type Parameters:
    X - Type of the exception to be thrown
    Parameters:
    exceptionSupplier - the supplying function that produces an exception to be thrown
    Returns:
    the value, if present
    Throws:
    X - if no value is present
    NullPointerException - if no value is present and the exception supplying function isnull
    X extendsThrowable
  - equals
```
public boolean equals(Object obj)
```
    Indicates whether some other object is "equal to" thisOptionalInt. The other object is considered equal if:
    it is also anOptionalInt 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:
    true if the other object is "equal to" this object otherwisefalse
    See Also:
    Object.hashCode(),HashMap
  - hashCode
```
public int hashCode()
```
    Returns the hash code of the value, if present, otherwise0 (zero) if no value is present.
    Overrides:
    hashCode in class Object
    Returns:
    hash code value of the present value or0 if no value is present
    See Also:
    Object.equals(java.lang.Object),System.identityHashCode(java.lang.Object)
  - toString
```
public String toString()
```
    Returns a non-empty string representation of thisOptionalInt 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 presentOptionalInts must be unambiguously differentiable.
    Returns:
    the string representation of this instance

Movatterモバイル変換

Class OptionalInt

Method Summary

Methods declared in class java.lang.Object

Method Detail

empty

of

getAsInt

isPresent

isEmpty

ifPresent

ifPresentOrElse

stream

orElse

orElseGet

orElseThrow

orElseThrow

equals

hashCode

toString