[FIXED] Main in static inner class produces ClassnotFoundException (despite $)

Issue

I'm using Java 11 and IntelliJ. See the snippet below:

public class Outer {
    public static class InnerA {
        public static void main(String[] args) {
            System.out.println("A");
        }
    }

    public static class InnerB {
        public static void main(String[] args) {
            System.out.println("B");
        }
    }
}

This results in no compile errors, but I cannot run it. Running it in the IDE result in a ClassNotFoundException

I tried using bash:

$ java Outer$InnerA.java

Which yields:

error: can't find main(String[]) method in class: Outer

I've tried rebuilding the project with no success.

Edit:

Since java 11 it is possible to execute a class without compiling it (javac). If I add a main() to Outer.java and execute it in the IDE or if I type the following in bash:

java Outer.java

Then the main() of Outer.java class is successfully called.

Solution

I found an answer myself.

IntelliJ:

I was using Gradle as my build tool. In IntelliJ this seems not to work. After I've change it to "IntelliJ IDEA" (see screenshot), I was finally was able to run it.

Bash:

Considering the new Java 11 feature i.e. "launching single-file programs", it seems it's not possible to run an inner static class like this way.

So after compiling and escaping the "$", I was able to run the file with:

$ java Outer\$InnerA

Thanks to user for hinting into the right direction.

Answered By - Younes El Ouarti
Answer Checked By - David Marino (JavaFixing Volunteer)