How to randomly generate some id and return it until the end of program execution?

I'm not sure if I asked a proper question in the title, but will try to do it here

So, let's say I have some programm in Java, which is starting and ending

And I need to use some random generated id in this programm, BUT this id should not changing during programm execution

So, basically I need this - create a function, which will generate and return random id once the programm starts, and I want to have an access to this id from everywhere in my project, BUT everytime while I'm calling a function to get an id, it should return the same id, which was randomly generated, when the programm started

Is it possible to do so ?