For example, change a user's firstname in Chinese and submit, the info will be changed to unreadable charactors and stored in db.

I added this line in the very beginning in CASAuthenticationValve.invoke and fixed the problem:
request.setCharacterEncoding("UTF-8");

Perhaps there are other ways to overcome this problem. If not, it would be better to add such a line to the source code.

Regards,

Shi Yusen/Beijing Langhua Ltd.