Usualy you solve the problems by just trying to create an MCVE, and you do that easily by trying to remove everything that has nothing to do with the problem/bug, and when you have just got the bug left, bam, there is the problem free from any other code that can steal your attention.
Omg you guys are so funny.
You really think you know more about my code then me?
If Im saying that I didnt change anything in my code and only reinstall Java,that is because is what I did!
I also dont think this is a bug,what propably happened was something during my previous installation went wrong.
To prove this is true,I had my first code I posted in the forum in a pen drive,in other words: No changes!
After I reinstall Java and see that worked with the actual code that I was messing around,I also tested with the initial code I’ve posted here and it also works.
Perhaps Im being ignorant but Im only trying to explain what really happened…
That does not prove anything. Threading and timing issues can show up only spontaneously and rarely, but still the code is wrong.
Try the same code on another machine, OS, runtime, switch to debug mode, run without IDE, add logging, do whatever and it could fail immediately.
Who knows.
Up for debate on that one.
You must have changed something.
Impossible.
Something must be different, like others have said, Java does not just have random bugs like you are stating. If so, lots of server backends would be completely f**ked.
EDIT:
Just so you know, IDE’s have brain farts, so I could believe that was the issue. Like sometimes my eclipse just gives up on imports and is like “nope, doesn’t exit mate”, when I clearly have the class open. Right. In. Front. Of. Me.
Maybe this could be the problem too.
After I reinstall Java I also downloaded another version of eclipse…
I believe We will never know 
Yes but we can quite reasonably assume that such a trivial issue is not Java’s fault, because Java is used by industries everywhere and I believe that Java also has salaried revision committees.