There is nothing related to JBoss in this matter. This is very basic JSP coding. Please refer to your text book on JSP.
The default charset of JSP is ISO-8859-1 which can display English and some European letters. If you want to display both traditional and simplifed Chinese at the same time, you can put the following at the beginning of your JSP
<%@ page contentType="text/html; charset=UTF-8" %>
and, better have the following in your html coding
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
If you want to display both only traditional Chinese, you can use UTF-8 or big5 as the charset.
If you want to display both only simplified Chinese, you can use UTF-8 or gb18030 as the charset. Note, gb18030 may also allow traditional Chinese, but I have not tried it. Becuase I prefer UTF-8.