mybatisplus自动配置了mapperLocations但是为什么仍无法映射？

如题，求解答，这是我在学习springboot整合mybatisplus时遇到一个困惑的问题，请教一下各位，这是导入的mybatisplus包，

在配置类MybatisPlusAutoConfiguration下配置好了mapperLocations

@Configuration
@ConditionalOnClass({SqlSessionFactory.class, SqlSessionFactoryBean.class})
@ConditionalOnSingleCandidate(DataSource.class)
@EnableConfigurationProperties({MybatisPlusProperties.class})
@AutoConfigureAfter({DataSourceAutoConfiguration.class, MybatisPlusLanguageDriverAutoConfiguration.class})
public class MybatisPlusAutoConfiguration implements InitializingBean

public class MybatisPlusProperties {
    private static final ResourcePatternResolver resourceResolver = new PathMatchingResourcePatternResolver();
    private String configLocation;
    private String[] mapperLocations = new String[]{"classpath*:/mapper/**/*.xml"};

按理说应该在任意包的类路径下的所有mapper文件夹下任意路径下的所有xml都是sql映射文件。
但是当我在配置文件中没有配置mapperLocations时，，
则写在这个文件夹的mapper文件无法映射，

控制台输出

Invalid bound statement (not found): com.school.boot.mapper.UserMapper.getUser

这是我的UserMapper.xml

<?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.school.boot.mapper.UserMapper">
    <select id="getUser" resultType="com.school.boot.bean.User">
        select * from user where id = #{id}
    </select>
</mapper>

这是我的UserMapper.java

package com.school.boot.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.school.boot.bean.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {
//    @Select("select * from user where id = #{id}")
    User getUser(Integer id);
}

在此之外使用@select注解以及使用BaseMapper的方法都可以。

不用@select 要在文件中写ResultMap

new String[]{"classpath*:/mapper/**/*.xml"};
冒号后面少了一个空格