I create a test file(test.jsp) in two edition.
A.the test.jsp include the "<%@ page contentType="text/html; charset=UTF-8"%>"
the Chinese show normally.
test.jsp
Code:
<%@ page contentType="text/html; charset=UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP</title>
</head>
<body>
This is my JSP page.中文<br>
</body>
</html>

B. the test.jsp include the file of includes.jsp
test.jsp
Code:
<%@ include file="/WEB-INF/jsp/includes.jsp" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP</title>
</head>
<body>
This is my JSP page.中文<br>
</body>
</html>
includes.jsp
Code:
<%@ page contentType="text/html; charset=UTF-8"%>
when I save the test.jsp,the Eclipse will alert the encoding(ISO-8859-1) cannot convert some characters...

and look in IE the Chinese become to ??

the <%@ page contentType="text/html; charset=UTF-8"%> replace to <%@ page contentType="text/html; charset=GB2312"%> the problem is same.