Some Chinese characters in my JSP program are displayed as? What should I do?

<% @ Page ContentType = "Text / HTML; Charset = GB2312" Language = "Java"%> Change to <% @ Page ContentType = "Text / HTML; Charset = GBK" Language = "Java"%>

Reason: The GB2312 character set is small, many words are not, it will become on the web?. It is no problem to change to GBK.