Ibatis Vo 中含有List<String>

<resultMap type="com.card.transaction.payment.pojo.sql.Tempab" id="selectab">      <result property="task" column="task"/>      <collection property="list" column="productname" ofType="java.lang.String">         <result column="productname"/>      </collection>   </resultMap>      <select id="selectTM" resultMap="selectab">      select task,productname from a,b where a.id=b.id   </select>