使用场景：

使用多数据源时，自定义创建SqlSessionFactory对象，没有正确读取到mybatis-config.xml配置，导致下划线驼峰映射失效，sql语句输出不显示等问题。

解决方案：

    @Bean(name = "UserSqlSessionFactory")
    public SqlSessionFactory dataLgSqlSessionFactory(@Qualifier("UserDataDataSource") DataSource dataSource, MybatisProperties mybatisProperties) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/user/**/*.xml"));
        bean.setConfigLocation(new ClassPathResource("mybatis-config.xml"));
        return bean.getObject();
    }

 mybatis-config.xml文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <setting name="lazyLoadingEnabled" value="true"/>
        <setting name="aggressiveLazyLoading" value="false"/>  <!-- 按需加载对象 -->
        <setting name="logImpl" value="STDOUT_LOGGING"/>
        <setting name="useGeneratedKeys" value="true"/>
    </settings>



</configuration>