Client and backend. This class is shared: the same code is compiled into your app and into your server, so everything on this page works in both.

public interface Collector<T, A, R>

How Stream.collect(Collector) folds the elements of a stream into a result: a container to start from, a step per element, a way to merge two containers and a last step that turns the container into the result.

Nested types

enum Collector.Characteristics What a collector says about itself.

Methods

`public abstract` `Supplier<A> supplier()`
`public abstract` `BiConsumer<A, T> accumulator()`
`public abstract` `BinaryOperator<A> combiner()`
`public abstract` `Function<A, R> finisher()`
`public abstract` `Set<Collector.Characteristics> characteristics()`
`public static <T, R>` `Collector<T, R, R> of(Supplier<R> supplier, BiConsumer<R, T> accumulator, BinaryOperator<R> combiner, Collector.Characteristics... characteristics)`
`public static <T, A, R>` `Collector<T, A, R> of(Supplier<A> supplier, BiConsumer<A, T> accumulator, BinaryOperator<A> combiner, Function<A, R> finisher, Collector.Characteristics... characteristics)`

Method details

supplier

public abstract Supplier<A> supplier()

accumulator

public abstract BiConsumer<A, T> accumulator()

combiner

public abstract BinaryOperator<A> combiner()

finisher

public abstract Function<A, R> finisher()

characteristics

public abstract Set<Collector.Characteristics> characteristics()

of

public static <T, R> Collector<T, R, R> of(Supplier<R> supplier, BiConsumer<R, T> accumulator, BinaryOperator<R> combiner, Collector.Characteristics... characteristics)

of

public static <T, A, R> Collector<T, A, R> of(Supplier<A> supplier, BiConsumer<A, T> accumulator, BinaryOperator<A> combiner, Function<A, R> finisher, Collector.Characteristics... characteristics)