when you run a terminal in linux, it usually starts out in you home directory. you wouldn't be able to see the .bash_profile file since it is hidden. ( if you didn't know already, files that start with a . ( dot ) are normally hidden )
to see if you actually have the file, try typing "ls -al" this will display all the files and dirs.
to make the path, try editing your .bash_profile or .bashrc either will do. if they are not there, create them. no harm in trying.
try placing
PATH=$PATH:/this/is/your/java/directory
this will add your java directory to the existing path.
to try if this works, try typing
#echo $PATH
hope this helps.