Class inside class

Question

public class FirstClass
{
    private FirstClass()
    {
        new Thread(new Thread()).start();
    }

    public static void checkSomething(FirstClass clas)
    {
        //doing something
    }
    private class Thread implements Runnable
    {

        @Override
        public void run() {
            checkSomething(????);
        }

    }

    public static void main(String[] args)
    {
        new FirstClass();
    }
}

my question is, what to write in ???? to get class FirstClass, i cannot write "this", coz i would get Thread.

Answer 1

You can write FirstClass.this to access the enclosing class instance.