intellij run configuration can't find spring boot class

Question

I am trying to create a run configuration for a spring boot app, but Intellij can't find the main class of the spring boot app (Usually it is automatically populated). I tried adding the class by searching the project structure, but Intellij won't let me add that application's main file to 'Main class' of the configuration. How can I make Intellij detect the class?

Project Directory:

rootfolder
   > springBootBackEnd
   > angularUI

I have the module set to 'rootfolder' and the content root is the rootfolder

Answer 1

Problem may be that you have badly configured IDEA project files.

Close IDEA, delete all .idea files and reimport project.

Answer 2

The same issue occured to me. In my case, it was the project JDK that was not set. The module JDK was set, but not the project one.

Go to File > Project Structure > Project > Project SDK to solve the issue.