java 四舍五入 向上向下取整

long test  =  5001;

//四舍五入
long roundNum = (long) Math.round((float) test/5);

//向上取整
long ceilNum = (long) Math.ceil((float) test/5);

//向下取整
long floorNum = (long) Math.floor((float) test/5);

System.out.println("四舍五入 向上取整  向下取整");
System.out.println(test/5);
System.out.println(roundNum + " " + ceilNum + " " + floorNum);

结果：

四舍五入 向上取整 向下取整
1000
1000 1001 1000