How to run a Java application right after tests without Maven?

I have to do a test task and I am stuck at one point. It's said: 'The entry point of the whole application should lay through tests.' As I understand it: main(args[]) method should run right after the tests if they were successful. I guess it's better not to use Maven but if there is no other way, well, let's forget about this restriction. It's also better to keep Java as plain as possible.

I'm not even sure which testing technology I should use. JUnit? I did't find anything related to my problem in it. Something else? Is it even possible?

There is a possibility I understood it all wrong and I should do something different. If it's not the case I hope you will explain how to run a plain application right after the tests automaticly.