mybatis错误

问题1：在mybatis-config.xml中使用了正确的资源路径，但是仍然报not find的错误！！！

    <mappers>
        <mapper resource="com/louis/dao/UserMapper.xml"/>
    </mappers>

解决方法：①可以将资源放置在resource文件夹下

　　　　　②在pom.xml中添加如下代码

    <build>
        <finalName>mybatis-practise</finalName>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

问题2：出现Java.lang.ClassNotFoundException: Cannot find class: ${com.mysql.cj.jdbc.Driver},可以将$和{}删除，同理username和password部分出现问题也可以使用相同的方法。