Mybatis如何使用@Mapper和@MapperScan注解实现映射关系

/**
 * 用户信息Mapper动态代理接口
 * @author pan_junbiao
 **/
@Mapper
@Repository
public interface UserMapper
{
    /**
     * 新增用户，并获取自增主键
     */
    @Insert("INSERT INTO tb_user(user_account,user_password,blog_url,blog_remark) VALUES(#{userAccount},#{userPassword},#{blogUrl},#{blogRemark})")
    @Options(useGeneratedKeys = true, keyColumn = "user_id", keyProperty = "userId")
    //或者：@SelectKey(statement = "SELECT LAST_INSERT_ID()", keyColumn = "user_id", keyProperty = "userId",before = false, resultType = Integer.class)
    public int insertUser(UserInfo userInfo);
 
    /**
     * 修改用户
     */
    @Update("UPDATE tb_user SET user_account = #{userAccount} ,user_password = #{userPassword} ,blog_url=#{blogUrl} ,blog_remark=#{blogRemark} WHERE user_id = #{userId}")
    public int updateUser(UserInfo userInfo);
 
    /**
     * 删除用户
     */
    @Delete("DELETE FROM tb_user WHERE user_id = #{userId}")
    public int deleteUser(int userId);
 
    /**
     * 根据用户ID，获取用户信息
     */
    @Select("SELECT * FROM tb_user WHERE user_id = #{userId}")
    public UserInfo getUserById(int userId);
}

package com.pjb;
 
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
/**
 * SpringBoot启动类
 * @author pan_junbiao
 **/
@MapperScan("com.pjb.mapper")
@SpringBootApplication
public class SpringbootMybatisDemoApplication
{
    public static void main(String[] args)
    {
        SpringApplication.run(SpringbootMybatisDemoApplication.class, args);
    }
}

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mybatis="http://mybatis.org/schema/mybatis-spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://mybatis.org/schema/mybatis-spring
http://mybatis.org/schema/mybatis-spring.xsd">
<mybatis:scan base-package="com.mybatis.x.mappers" />
</beans>

@Configuration
@MapperScan("com.mybatis.x.mappers")
public class AppConfig
{
@Bean
public DataSource dataSource()
{
return new PooledDataSource("com.mysql.jdbc.Driver",
"jdbc:mysql://localhost:3306/test", "root", "root");
}
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception
{
SqlSessionFactoryBeansessionFactory = new
SqlSessionFactoryBean();
sessionFactory.setDataSource(dataSource());
return sessionFactory.getObject();
}
}

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.mybatis3.mappers" />
</bean>