轉自:http://blog.csdn.net/dream0129/article/details/72773392

其實解決方案特別簡單。

fild->Invalidate Caches / Restart.

確定

1. Open IntelliJ IDEA
2. Select the File menu
3. Select the Invalidate Caches / Restart... menu.
   Once selected you get a pop-up with a bunch of options.
4. Select Invalidate and Restart
   and before doing that make sure you saved all your changes else it might delete some unsaved changes.