Java Web application cookie lost?

I got one new change to do in our java web application.I have not been in it since 2 or 4 months and forgot some of its settings.

First of all my jboss refuses to run from eclipse!i was very worried about it, but later i re-configured it as a "dynamic web application" project in eclipse.

So when jboss runs finally, i logged in it and a big blast! it redirected me to error page. I checked the logs but i can't find anything.I was thinking that even i have not chnaged the things in code,configuration etc. then also it stucks here?

But suddenly, a spark happned and i remembered that we set domain for cookies in most web applications.And that thing sucks in local environment.
cookie setting code:

Cookie c1 = new Cookie(name, value);
c1.setDomain(domainName);

So i just commented out c1.setDomain(domainName); and my application is ok.

via javaLibs Blog