is there any log file maintained by confluence to store user data?

[poonam chaudhari]

if yes then where these log files are stored? how to track them?

[poonam chaudhari]

if possible how to read these files using java?

[Nik Eklund]

What sort of data are you looking for? Additionally, is this an OnDemand Confluence instance (hosted by us) or a locally installed instance. (I ask because the account linked to your email address is a downloaded version license and the answer to your question will depend on which way you are running the application.)