com.landawn.abacus.util

Class OptionalDouble

java.lang.Object

com.landawn.abacus.util.OptionalDouble

All Implemented Interfaces:

java.lang.Comparable<OptionalDouble>

public final class OptionalDouble
extends java.lang.Object
implements java.lang.Comparable<OptionalDouble>

Note: It's copied from OpenJDK at: http://hg.openjdk.java.net/jdk8u/hs-dev/jdk
A container object which may or may not contain a double value. If a value is present, isPresent() will return true and get() 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).

This is a value-based class; use of identity-sensitive operations (including reference equality (==), identity hash code, or synchronization) on instances of OptionalDouble may have unpredictable results and should be avoided.

Since:

1.8

Method Summary

Modifier and Type	Method and Description
java.util.OptionalDouble	__()
Optional<java.lang.Double>	boxed()
int	compareTo(OptionalDouble optional)
static OptionalDouble	empty() Returns an empty OptionalDouble instance.
boolean	equals(java.lang.Object obj) Indicates whether some other object is "equal to" this OptionalDouble.
<E extends java.lang.Exception> OptionalDouble	filter(Try.DoublePredicate<E> predicate)
<E extends java.lang.Exception> OptionalDouble	flatMap(Try.DoubleFunction<OptionalDouble,E> mapper)
static OptionalDouble	from(java.util.OptionalDouble optional)
double	get() If a value is present in this OptionalDouble, 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.
<E extends java.lang.Exception> void	ifPresent(Try.DoubleConsumer<E> consumer) Have the specified consumer accept the value if a value is present, otherwise do nothing.
<E extends java.lang.Exception,E2 extends java.lang.Exception> void	ifPresentOrElse(Try.DoubleConsumer<E> action, Try.Runnable<E2> emptyAction) If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
boolean	isPresent() Return true if there is a value present, otherwise false.
<E extends java.lang.Exception> OptionalDouble	map(Try.DoubleUnaryOperator<E> mapper)
<T,E extends java.lang.Exception> Nullable<T>	mapToObj(Try.DoubleFunction<T,E> mapper)
static OptionalDouble	of(double value) Return an OptionalDouble with the specified value present.
static OptionalDouble	ofNullable(java.lang.Double val) Returns an empty OptionalDouble if the specified Double is null.
double	orElse(double other) Return the value if present, otherwise return other.
<E extends java.lang.Exception> double	orElseGet(Try.DoubleSupplier<E> other) Return the value if present, otherwise invoke other and return the result of that invocation.
double	orElseThrow() If a value is present, returns the value, otherwise throws NoSuchElementException.
<X extends java.lang.Throwable> double	orElseThrow(Supplier<? extends X> exceptionSupplier) Return the contained value, if present, otherwise throw an exception to be created by the provided supplier.
double	orZero()
DoubleStream	stream()
java.lang.String	toString() Returns a non-empty string representation of this object suitable for debugging.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Method Detail

empty

public static OptionalDouble empty()

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

Returns:

an empty OptionalDouble.

ofNullable

public static OptionalDouble ofNullable(java.lang.Double val)

Returns an empty OptionalDouble if the specified Double is null.

Parameters:

val -

Returns:

of

public static OptionalDouble of(double value)

Return an OptionalDouble with the specified value present.

Parameters:

value - the value to be present

Returns:

an OptionalDouble with the value present

from

public static OptionalDouble from(java.util.OptionalDouble optional)

get

public double get()
           throws java.util.NoSuchElementException

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

Returns:

the value held by this OptionalDouble

Throws:

java.util.NoSuchElementException - if there is no value present

See Also:

isPresent()

isPresent

public boolean isPresent()

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

Returns:

true if there is a value present, otherwise false

ifPresent

public <E extends java.lang.Exception> void ifPresent(Try.DoubleConsumer<E> consumer)
                                               throws E extends java.lang.Exception

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:

java.lang.NullPointerException - if value is present and consumer is null

E extends java.lang.Exception

ifPresentOrElse

public <E extends java.lang.Exception,E2 extends java.lang.Exception> void ifPresentOrElse(Try.DoubleConsumer<E> action,
                                                                                           Try.Runnable<E2> emptyAction)
                                                                                    throws E extends java.lang.Exception,
                                                                                           E2 extends java.lang.Exception

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

Parameters:

action -

emptyAction -

Throws:

E extends java.lang.Exception

filter

public <E extends java.lang.Exception> OptionalDouble filter(Try.DoublePredicate<E> predicate)
                                                      throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

map

public <E extends java.lang.Exception> OptionalDouble map(Try.DoubleUnaryOperator<E> mapper)
                                                   throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

mapToObj

public <T,E extends java.lang.Exception> Nullable<T> mapToObj(Try.DoubleFunction<T,E> mapper)
                                                       throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

flatMap

public <E extends java.lang.Exception> OptionalDouble flatMap(Try.DoubleFunction<OptionalDouble,E> mapper)
                                                       throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

orZero

public double orZero()

orElse

public double orElse(double 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

orElseGet

public <E extends java.lang.Exception> double orElseGet(Try.DoubleSupplier<E> other)
                                                 throws E extends java.lang.Exception

Return the value if present, otherwise invoke other and return the result of that invocation.

Parameters:

other - a DoubleSupplier whose result is returned if no value is present

Returns:

the value if present otherwise the result of other.getAsDouble()

Throws:

java.lang.NullPointerException - if value is not present and other is null

E extends java.lang.Exception

orElseThrow

public <X extends java.lang.Throwable> double orElseThrow(Supplier<? extends X> exceptionSupplier)
                                                   throws X extends java.lang.Throwable

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

Type Parameters:

X - Type of the exception to be thrown

Parameters:

exceptionSupplier - The supplier which will return the exception to be thrown

Returns:

the present value

Throws:

X - if there is no value present

java.lang.NullPointerException - if no value is present and exceptionSupplier is null

X extends java.lang.Throwable

orElseThrow

public double orElseThrow()
                   throws java.util.NoSuchElementException

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

Returns:

Throws:

java.util.NoSuchElementException - - if no value is present

compareTo

public int compareTo(OptionalDouble optional)

Specified by:

compareTo in interface java.lang.Comparable<OptionalDouble>

stream

public DoubleStream stream()

boxed

public Optional<java.lang.Double> boxed()

__

public java.util.OptionalDouble __()

equals

public boolean equals(java.lang.Object obj)

Indicates whether some other object is "equal to" this OptionalDouble. The other object is considered equal if:

• it is also an OptionalDouble and;
• both instances have no value present or;
• the present values are "equal to" each other via Double.compare() == 0.

Overrides:

equals in class java.lang.Object

Parameters:

obj - an object to be tested for equality

Returns:

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

hashCode

public int hashCode()

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

Overrides:

hashCode in class java.lang.Object

Returns:

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

toString

public java.lang.String toString()

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.

Overrides:

toString in class java.lang.Object

Returns:

the string representation of this instance