public final class ModuleRegistry {

    private static final class Holder {
        private static final ModuleRegistry instance = new ModuleRegistry();
    }

    private ModuleRegistry() {
        Reflections reflections = new Reflections("");
        // Some components registration
    }

    public static ModuleRegistry getInstance() {
        return Holder.instance;
    }
}

public final class Main{
    public static void main(String[] args){
        // Let's eagerly initialize everything
        ModuleRegistry.getInstance();

       // Do all the work
    }
}