java 获取传入值的区间

/**
     * 获取值的区间
     *
     * @param num 值
     */
    public static Map<String, Integer> getNumSection(Integer num) {
        Map<String, Integer> map = new HashMap();
        int length = num.toString().length();
        if (length == 1) {   //判断是否为个数 1234567890
            map.put("maxNum", 0);
            map.put("minNum", 10);
            return map;
        }
        String count = "";
        for (int i = 1; i < length; i++) {
            count += "0";
        }
        String shou = num.toString().substring(0, 1); //获取首位
        int minNum = Integer.parseInt(shou + count);//最小
        int maxNum = Integer.parseInt(String.valueOf(Integer.parseInt(shou) + 1) + count);//最大
        map.put("maxNum", maxNum);
        map.put("minNum", minNum);
        return map;
    }