函数式遍程----Function

Consumer定义

@FunctionalInterface
public interface Consumer<T> {

    void accept(T t);

    default Consumer<T> andThen(Consumer<? super T> after) {
        Objects.requireNonNull(after);
        return (T t) -> { accept(t); after.accept(t); };
    }
}

其核心的方法如下：

void accept(T t){

}

default Consumer andThen(Consumer<? super T> after){

}

Consumer在处理的时候是没有返回值

Function<T,R>  

@FunctionalInterface
public interface Function<T, R> {

    /**
     * Applies this function to the given argument.
     *
     * @param t the function argument
     * @return the function result
     */
    R apply(T t);
}

public int compute(int a, Function<Integer, Integer> function) {
    int result = function.apply(a);
    return result;
}

test.compute(5,value -> value * value) //25 计算平方
test.compute(5,value -> value + value) //10 求和
test.compute(5,value -> value - 2) //3