public class MathTest { public static void main(String[] args) { // 四舍五入 long round = Math.round(1.499); long round2 = Math.round(1.5); System.out.println(round); System.out.println(round2); // 向上取整 int s = (int)Math.ceil(1.1); System.out.println(s); // 向下取整 System.out.println((int)Math.floor(1.6)); } }