Yes, java via the JDK is supported.
It is installed into:
On some servers it may be installed at :
If you cannot find it at any of these locations, enter a support ticket to have your server updated.
Yes, mod_rewrite is fully supported. mod_rewrite is a great apache module and we are happy to allow its use.
You can enter mod_rewrite rules into a standard .htaccess file. The rules will have effect over all files in that directory and in all directories “below” that directory.
Please note that due to the complex nature of mod_rewrite rules, we are not able to offer debugging assistance with your rules.