What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

Question

Under the target folder in IntelliJ for a Java project I created, I have a few java source files in the package. Beside each file the \'J\' icon has a red circle with a lin

Answer 1

It means those files aren't part of the project settings.

Answer 2

The first answer from irreputable above that starts out with "you need to specify the source dir" is correct, but I don't see him telling you the easy way to do so.

Simply right click on the java sources folder ("java" under src/main/java if it is a Maven project for example) and select Mark Directory As > Sources Root (see screenshot below).

Answer 3

I downloaded a project from github with .idea folder. After deleting that folder, everything was ok.

Answer 4

Find all IntelliJ (v15) symbols over here: https://www.jetbrains.com/idea/help/symbols.html

This site states that this icon stands for "Java class located out of the source root. Refer to the section Configuring Content Roots for details."

Answer 5

Maybe your project has not been as android project by android studio, please make sure that plugin 'android support' has been enabled（Android Studio Preferences -> Plugins -> Select Android Support）

Answer 6

If it is a maven project

1. right click on the pom.xml
2. Add As Maven Project

Thanks