org.apache.ibatis.builder.IncompleteElementException: Could not find result map java.lang.String

今天写个mybatis配置意外发现一个错误，记录一下：

错误的配置：

<select id="findExpertMessage" resultMap="java.lang.String">
      select t.strPhoneId FROM expert e
     LEFT JOIN termuser t ON t.ID = e.USER_ID
    where e.STATE = 3
 </select>

导致 Could not find result map java.lang.String

正确的配置：

<select id="findExpertMessage" resultType="java.lang.String">
      select t.strPhoneId FROM expert e
     LEFT JOIN termuser t ON t.ID = e.USER_ID
    where e.STATE = 3
 </select>