统计返回的Decimal/long型数据转换问题

　　mysql数据库在进行统计时候，返回的count()是个long型，sum()返回的是bigDecimal类型，前段需要的是int型故而需要进行转换。

 <select id="getDeviceRentNum" parameterType="map" resultType="map">
    SELECT SUM(IF(f.`rent`=1,1,0)) rentNum, COUNT(d.`id`) deviceTotal
    FROM d_device d INNER JOIN d_device_fields f ON d.`id`=f.`device_id`
    WHERE d.`del_flag`=0 AND f.`del_flag`=0 AND d.`company_id`=#{companyId} 
    <if test="productId!=null and productId!=''">AND d.`product_id`=#{productId}</if>
    </select>
    <select id="getDeviceSoldNum" parameterType="map" resultType="Integer">
    SELECT COUNT(d.id) soldNum FROM d_device_fields f INNER JOIN  d_device d ON f.device_id=d.id INNER JOIN d_device_user_bind dub ON d.id=dub.device_id 
        WHERE d.del_flag=0 AND dub.del_flag=0 AND f.rent!=1 AND  d.`company_id`=#{companyId} 
    <if test="productId!=null and productId!=''">AND d.`product_id`=#{productId}</if>

Service 层转换

if(sign==2){
            Map<String, Object> resultMap = new HashMap<String,Object>();
            Map<String, Object> rentMap = deviceMapper.getDeviceRentNum(paramMap);
            Integer soldNum = deviceMapper.getDeviceSoldNum(paramMap);
            Integer rentNum = ((BigDecimal)rentMap.get("rentNum")).intValue();
            String dTotal = ((Long)rentMap.get("deviceTotal")).toString();
            Integer deviceTotal = Integer.valueOf(dTotal);
            Integer forSaleNum = (deviceTotal-soldNum-rentNum);
            resultMap.put("soldNum",soldNum );
            resultMap.put("rentNum", rentNum);
            resultMap.put("forSaleNum", forSaleNum);
            resultMap.put("deviceTotal",deviceTotal);
            return resultMap;
                }

经过如此转换方可以，否则会报错的，报错如下：

java.lang.ClassCastException: java.lang.Long cannot be cast to java.math.BigDecimal 之类的