这个问题是因为maven的build节点接管了资源拷贝。这样在IDEA中配置的resource资源就不会被正确的拷贝到Class文件夹底下了。这里只需要在pom文件中加上相关属性就可以

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>config/*.properties</include>
                <include>*.xml</include>
            </includes>
        </resource>
    </resources>
</build>