Hi I have solved the problem.
The problem is => I am using the tiles plugin in struts 2
and in BaseLayout page,I have
this line is creating the problem
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
after removing the line it works just fine
Although I did not get any reason for this but this trick just work for me,I have got this solution from this link
http://www.mkyong.com/struts2/struts-2-chinese-localization-issue/
Thanks