向上取整用：Math.ceil(double a)

向下取整用：Math.floor(double a)

        int a = 7;
        int b = 5;
        BigDecimal aBig = new BigDecimal(a);
        BigDecimal bBig = new BigDecimal(b);
        //向上取整
        int num1 = (int)Math.ceil(aBig.divide(bBig).doubleValue());
        //向下取整
        int num2 = (int)Math.floor(aBig.divide(bBig).doubleValue());
        System.out.println("正常值："+aBig.divide(bBig));
        System.out.println("向上取整:"+num1);
        System.out.println("向下取整:"+num2);

 

参考：java 除法向上，向下取整 - 秋香姑娘请你不要紧张 - 博客园