I'm not sure if there's already a thread like this, so mod sorry if i broke a rule here.
To update your java in Samsung GT-S5230(star) and play 1Mb+ java games.

1. Install a java game(1mb+ .jar) and exit to main
2. Dial admin code *#6984125*#
3. Go to Internals
4. Enter master key *#9072641*# and confirm
5. Go to Storage settings
6. Select Update java DB
7. Exit after the update and play the game you installed earlier.

Note: Do this everytime you install a 1mb+ java game with error "no memory available" and the game should work. Not tested on other phones.