当MyBatis传入的参数数据类型为java map时，如何执行更新操作？

<update id="updateUser" parameterType="java.util.Map">
  UPDATE user_table
  <set>
    <if test="name != null">name = #{name},</if>
    <if test="age != null">age = #{age},</if>
  </set>
  WHERE id = #{id}
</update>

Map<String, Object> paramMap = new HashMap<>();
paramMap.put("id", 1);
paramMap.put("name", "John");
paramMap.put("age", 30);

SqlSession sqlSession = sessionFactory.openSession();
sqlSession.update("updateUser", paramMap);
sqlSession.commit();
sqlSession.close();