I don't know how Host Gator works, but in DreamHost PHP and Apache runs with your username. WordPress would then use your username, since it is a PHP script, but it can change from host to host. Probably java4u is a user in the system, maybe not yours, but someone who shares the machine with you.
Shared hosting, although with sometimes unlimited bandwidth and space, cannot have unlimited resources like memory and processor time. That was my problem with Dreamhost, as my WordPress got many access, I had to move to a Virtual Private Server, a VPS.
There are many VPS hosting companies, with different price ranges. If you are brave enough, you can go to Linode or Slicehost and build your server from scratch (install OS, PHP, MySQL, WebServer, etc). Or you can go easy and use Host Gator or Dream Host, with their VPS with everything already installed. You can check out for other companies too.