Occasional pit compiled by idea

idea Compilation problems , It's usually a modification complie To the corresponding maven edition

1、File -> Project Structure -> Modules Select corresponding module, modify Language Level

2、File -> Settings -> Build,Execution,Deployment -> Compiler -> Java Compiler Modify the corresponding java edition

But if it still appears maven The import class or compilation cannot work , Then only invalid caches And restart

But occasionally there will be failures , At this time, you can only manually delete the index and cache , Delete the corresponding version of the following directory idea The catalog of （ The author is ：C:\Users\Administrator\AppData\Local\JetBrains\IntelliJIdea2021.2）

C:\Users\Administrator\AppData\Local\JetBrains