函数式接口
就是只定义一个抽象方法(用来表示行为)的接口,用作Lambda表达式的类型。
public interface Comparator{ int compare(T o1, T o2);}public interface Runnable{ void run();}
java.util.function中给到的部分函数式接口
| 函数式接口 | 函数描述符 | 方法 | default方法 |
|---|---|---|---|
| Predicate<T> | T->boolean | test(T t) | and,negate,or,isEqual |
| Consumer<T> | T->void | accept(T t) | andThen |
| Function<T,R> | T->R | apply(T t) | compose,andThen,identity |
| Supplier<T> | ()->T | get() | 无 |
| BiPredicate<L,R> | (L,R)->boolean | test(L l, R r) | and,negate,or |
| BiConsumer<T,U> | (T,U)->void | accept(T t, U u) | andThen |
| BiFunction<T,U,R> | (T,U)->R | apply(T t, U u) | andThen |
| UnaryOperator<T> | T->T | ||
| BinaryOperator<T> | (T,T)->T |
| 原始类型特化 |
|---|
| Predicate |
| IntPredicate |
| LongPredicate |
| DoublePredicate |
| Consumer |
| IntConsumer |
| LongConsumer |
| DoubleConsumer |
| Function<T,R> |
| IntFunction<R>, |
| IntToDoubleFunction, |
| IntToLongFunction, |
| LongFunction<R>, |
| LongToDoubleFunction, |
| LongToIntFunction, |
| DoubleFunction<R>, |
| ToIntFunction<T>, |
| ToDoubleFunction<T>, |
| ToLongFunction<T> |
| Supplier<T> |
| BooleanSupplier |
| IntSupplier |
| LongSupplier |
| DoubleSupplier |
| UnaryOperator<T> |
| IntUnaryOperator |
| LongUnaryOperator |
| DoubleUnaryOperator |
| BinaryOperator<T> |
| IntBinaryOperator |
| LongBinaryOperator |
| DoubleBinaryOperator |
| BiConsumer<T,U> |
| ObjIntConsumer<T> |
| ObjLongConsumer<T> |
| ObjDoubleConsumer<T> |
| BiFunction<T,U,R> |
| ToIntBiFunction<T,U> |
| ToLongBiFunction<T,U> |
| ToDoubleBiFunction<T,U> |