| Return type | Name and parameters |
|---|---|
boolean
|
asBoolean()
Coerce an Optional instance to a boolean value.
|
Optional
|
collect(Closure transform)
If the optional contains a value, returns an optional containing the transformed value obtained using the transform closure
or otherwise an empty optional.
|
Optional
|
filter(Class type)
Tests given value against specified type and changes generics of result. |
OptionalDouble
|
mapToDouble(ToDoubleFunction mapper)
If a value is present in the OptionalDouble, returns an OptionalDouble
consisting of the result of applying the given function to the value or else empty.
|
OptionalInt
|
mapToInt(ToIntFunction mapper)
If a value is present in the OptionalInt, returns an OptionalInt
consisting of the result of applying the given function to the value or else empty.
|
OptionalLong
|
mapToLong(ToLongFunction mapper)
If a value is present in the OptionalLong, returns an OptionalLong
consisting of the result of applying the given function to the value or else empty.
|
Stream
|
stream()
If a value is present in the Optional, returns a Stream with the value as its source or else an empty stream. |
addShutdownHook, any, any, asBoolean, asType, average, collect, collect, collect, contains, count, dump, each, eachWithIndex, equals, every, every, find, find, findAll, findAll, findIndexOf, findIndexOf, findIndexValues, findIndexValues, findLastIndexOf, findLastIndexOf, findResult, findResult, flatten, getAt, getMetaClass, getMetaPropertyValues, getProperties, grep, grep, groupBy, groupBy, hasProperty, identity, inject, inject, inspect, invokeMethod, is, isCase, iterator, join, metaClass, print, print, printf, printf, println, println, println, putAt, respondsTo, respondsTo, setMetaClass, size, split, sprintf, sprintf, stream, sum, sum, tap, toArrayString, toSpreadMap, toString, use, use, use, with, with, withTraits
Coerce an Optional instance to a boolean value.
assert !Optional.empty().asBoolean() assert Optional.of(1234).asBoolean()
true if a value is present, otherwise falseIf the optional contains a value, returns an optional containing the transformed value obtained using the transform closure
or otherwise an empty optional.
assert Optional.of("foobar").collect{ it.size() }.get() == 6
assert !Optional.empty().collect{ it.size() }.isPresent()
transform - the closure used to transform the optional value if presentTests given value against specified type and changes generics of result.
This is equivalent to: self.filter(it -> it instanceof Type).map(it -> (Type) it)
assert !Optional.empty().filter(Number).isPresent()
assert !Optional.of('x').filter(Number).isPresent()
assert Optional.of(1234).filter(Number).isPresent()
assert Optional.of(1234).filter(Number).get().equals(1234)
If a value is present in the OptionalDouble, returns an OptionalDouble
consisting of the result of applying the given function to the value or else empty.
assert !Optional.empty().mapToDouble(x -> Math.PI).isPresent()
assert Optional.of('x').mapToDouble(x -> Math.PI).getAsDouble() == Math.PI
If a value is present in the OptionalInt, returns an OptionalInt
consisting of the result of applying the given function to the value or else empty.
assert !Optional.empty().mapToInt(x -> 42).isPresent()
assert Optional.of('x').mapToInt(x -> 42).getAsInt() == 42
If a value is present in the OptionalLong, returns an OptionalLong
consisting of the result of applying the given function to the value or else empty.
assert !Optional.empty().mapToLong(x -> 42L).isPresent()
assert Optional.of('x').mapToLong(x -> 42L).getAsLong() == 42L
If a value is present in the Optional, returns a Stream with the value as its source or else an empty stream.