I figured out 2 parts of this

This is what I have so far:

public class Solution
{
    public static AtomicInteger factoryNumber = new AtomicInteger(1);
    public static void main(String[] args)
    {
        class EmulatorThreadFactoryTask implements Runnable
        {
            @Override
            public void run()
            {
                emulateThreadFactory();
            }
        }

        ThreadGroup group = new ThreadGroup("firstGroup");
        Thread thread = new Thread(group, new EmulatorThreadFactoryTask());

        ThreadGroup group2 = new ThreadGroup("secondGroup");
        Thread thread2 = new Thread(group2, new EmulatorThreadFactoryTask());

        thread.start();
        thread2.start();
    }

    private static void emulateThreadFactory()
    {
        AmigoThreadFactory factory = new AmigoThreadFactory();
        Runnable r = new Runnable()
        {
            @Override
            public void run()
            {
                System.out.println(Thread.currentThread().getName());
            }
        };
        factory.newThread(r).start();
        factory.newThread(r).start();
        factory.newThread(r).start();
    }

    public static class AmigoThreadFactory implements ThreadFactory
    {
        public int factoryNumber = Solution.factoryNumber.getAndIncrement();
        public AtomicInteger threadNumber = new AtomicInteger(1);

        @Override
        public Thread newThread(Runnable r)
        {
            return new Thread(r,"GN-pool-" + factoryNumber + "-thread-" + threadNumber.getAndIncrement());
        }
    }
}

Which, when run, gives:

GN-pool-1-thread-1
GN-pool-1-thread-2
GN-pool-2-thread-1
GN-pool-2-thread-2
GN-pool-1-thread-3
GN-pool-2-thread-3

This looks enough like the task conditions output that I think I have accomplished the factoryNumber and threadNumber part. But I'm pretty stuck on the GN piece. As far as within the main method, I could, for example, use thread2.getThreadGroup().getName() to get the piece of information I need for GN. But once the emulateThreadFactory() method is called, I lose that data. thread2 is not passed as information to that method, and since it's a static method I can't use this.getThreadGroup() either. By the time I enter that method, I no longer have access to which thread I entered it from.