springboot 报错Cannot find class:

查了很多资料，要么就是xml和dao没有对应起俩，要么就是问题出在了xml文件上，
我的问题是resultType的路径应该是 " . " 不是 " / ",如果你是copyPath的话，就会是 " / ",一定注意！！！！

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.sportplay.dao.UserDao">
    <select id="getUserMessage" resultType="com.example.sportplay.entity.User">
        SELECT * FROM easyUser WHERE username=#{username} AND password=#{password} AND state=1;
    </select>
</mapper>