List the files opened by a specific program/process

1. find the pid, i.e. process id, of the program/application. e.g. java

ps aux | grep java

2. use lsof to list the files opened by that process (where 13317 is the pid, e.g.).

lsof -p 13317

See Also: http://www.cyberciti.biz/faq/howto-linux-get-list-of-open-files/