打开设置（CTRL+ALT+S）搜索editor，找到“Code Completion”->点击Case sensitive completion后面的选择框，选中None，然后一路确定即可。
<build> <resources> <resource> <directory>${basedir}/src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> </resources> </build>
鼠标点击红色字，然后Intellij出现小红灯，选择Fetch external resource即可解决
原文：https://www.cnblogs.com/ICE_Inspire/p/9721360.html