c:imported jsp cannot show Chinese chars

[Huang Teng Shiu]

Hi all , I'm from Taiwan , newbie to JSTL .
I encountered a serious problem about Chinese big5 encoding in JSTL .
For example , a index.jsp wants to include header.jsp
The first two lines of index.jsp are :
<%@ page language="java" contentType="text/html;charset=Big5" %>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
All chinese chars inside index.jsp can be shown correctly .
Then , I want to insert header.jsp . I've tried many ways but in vain . All Chinese (big5) words in header.jsp cannot be correctly displayed. ex:
<jsp:include page="jsp/header.jsp"/>
Chinese words become bad codes.
JSTL way :
<c:import url="jsp/header.jsp"/>
Chinese chars become question marks ("???")
<%@ include file="jsp/header.jsp" %>
com.caucho.xml.XmlParseException: stream:26: illegal character
ref at `?' (\ufffd)

Adding character-encoding='big5' in web.xml or not seems won't change the result.
What else can I do ? Can somebody help me ? Thank you.
Server environment :
Linux locale : LANG=zh_TW
Servlet Container : Resin 2.1.6
JSTL Libraries:
jstl.jar : version 1.0.2
standard.jar : version 1.0.2