Modifier and Type
Method and Description
static <T> Optional<T>
empty
Returns an empty Optional instance.
boolean
equalsObject obj)
Indicates whether some other object is “equal to” this Optional.
Optional<T>
filterPredicate<? super T> predicate)
If a value is present, and the value matches the given predicate,
return an Optional describing the value, otherwise return an
empty Optional.
<U> Optional<U>
flatMapFunction<? super T,Optional<U>> mapper)
If a value is present, apply the provided Optional-bearing
mapping function to it, return that result, otherwise return an empty
Optional.
T
get
If a value is present in this Optional, 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.
void
ifPresentConsumer<? super T> consumer)
If a value is present, invoke the specified consumer with the value,
otherwise do nothing.
boolean
isPresent
Return true if there is a value present, otherwise false.
<U> Optional<U>
mapFunction<? super T,? extends U> mapper)
If a value is present, apply the provided mapping function to it,
and if the result is non-null, return an Optional describing the
result.
static <T> Optional<T>
of
Returns an Optional with the specified present non-null value.
static <T> Optional<T>
ofNullable
Returns an Optional describing the specified value, if non-null,
otherwise returns an empty Optional.
T
orElseT other)
Return the value if present, otherwise return other.
T
orElseGetSupplier<? extends T> other)
Return the value if present, otherwise invoke other and return
the result of that invocation.
<X extends Throwable>
T
orElseThrowSupplier<? extends X> exceptionSupplier)
Return the contained value, if present, otherwise throw an exception
to be created by the provided supplier.
String
toString
Returns a non-empty string representation of this Optional suitable for
debugging.
