TimePeriod添加默认构造函数，解决json 反序列化问题。

fengxiang

2018-09-05 641d383dc93ae1f2b92c2a974cb64fb1f3bdebe9

 src/main/resources/mapper/HistoryMinutelyMapper.xml

@@ -38,7 +38,7 @@
            AVG(json->'$.${sensorKey}[0]') AS '${sensorKey}'

         </foreach>

      FROM

         history_minutely h

         history_${timeUnits} h

      WHERE

         h.time >= #{start}

      AND h.time <![CDATA[<]]> #{end}