Stream - interface Stream

제네릭 Stream

• Stream<T>

static methods

• of(T t) -> Stream<T>
• of(T... values) -> Stream<T>
• concat(Stream<T> a, Stream<T> b) -> Stream<T>
• generate(Supplier<T>) -> Stream<T>
• empty() -> Stream

Stream<Integer> -> IntStream

• stream.mapToInt(Integer::valueOf) -> IntStream
• stream.asIntStream() -> IntStream

IntStream -> Stream<Integer>

• intStream.boxed() -> Stream<Integer>
• intStream.mapToObj(T::new) -> Stream<T>

무한 Stream

• 생성 Pattern을 전달하면 무한 Stream 생성가능
• limit 메서드로 개수 조절
• Stream<T>.iterate(T seed, UnaryOperator<T> f) -> Stream<T>
  • 초기값 seed를 입력
  • 이전의 결과값으 다음의 입력값으로 사용
  • 0 : seed, 1 : f(seed), 2: f(f(seed)), ...
• Stream<T>.generate(Supplier<T>) -> Stream<T>