I created a new project in Eclipse called Lottery. The first thing that happened was I recieved a weird icon on my project that I never seen before.

I decided it was nothing and created a new class, called RandomNumberGenerator. Then it gave me the following error:
Implicit super constructor Object() is undefined for default constructor.
Must define an explicit constructor
I have no idea what the problem is. Could somebody help? I can’t create another class without an error!
Thanks in advance!
this will help you
in project property dialog , check that JRE System Liabrary is set properly or not in Java Build Path.
in same dialog check builders option , if you are using javascript code than this may be happed.