mybatis返回类型string，或者对象，均可用list<string>或者，list<对象>来接收

--------------------------------------eg 1------------------------------------

 <!-- 通过角色id查找权限数据 -->
<select id="findSysRoleFunctionById" parameterType="string" resultType="string">
select sf_id from sys_role_function where sr_id = #{srId}
</select>

返回string类型，可以用List<String>  findSysRoleFunctionById(String srId);

list<String>来接收

----------------------------------------------eg 2------------------------------------

  <resultMap id="BaseResultMap" type="com.bdf.rolemanager.vo.SysRoleVO" >
    <id column="sr_id" property="srId" jdbcType="VARCHAR" />
    <result column="sr_name" property="srName" jdbcType="VARCHAR" />
    <result column="srTypeName" property="srTypeName" jdbcType="VARCHAR" />
<result column="roleUserCount" property="roleUserCount" jdbcType="VARCHAR" />
    <result column="sr_stats" property="srStats" jdbcType="VARCHAR" />
    <result column="umName" property="umName" jdbcType="VARCHAR" />
<result column="um_id" property="umId" jdbcType="VARCHAR" />
    <result column="sr_create_time" property="srCreateTime" jdbcType="VARCHAR" />
    <result column="sr_describe" property="srDescribe" jdbcType="VARCHAR" />
<result column="sr_type" property="srType" jdbcType="VARCHAR" />
  </resultMap>

<!-- 通过id查找对象 -->
<select id="findSysRoleById" parameterType="string" resultMap="BaseResultMap">
select * from sys_role where sr_id = #{srId}
</select>

SysRoleVO findSysRoleById(String srId);   用对象接收或者List<SysRoleVO>接收均可