Java8 Funtion学习

andThen先执行自己再执行入参函数，compose反之

Function<Integer, Integer> f1 = n -> n * n;
        
Function<Integer, Integer> f2 = n -> n * n * 3;

System.out.println(f1.andThen(f2).apply(2));//先执行f1->2*2->4*4*3=48

System.out.println(f1.compose(f2).apply(2));//先执行f2->2*2*3->12*12=144