此類問題主要爲CAS系統與web項目對頁面編碼的設置不一致造成的。
解決方法如下：
1. 在CAS服務端的WEB-INF/web.xml中添加：
<filter>
<filter-name>Set Character Encoding</filter-name>
<filter-class>filters.SetCharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>ignore</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
2. 修改
WEB-INF/view/jsp/protocol/2.0/casServiceValidationSuccess.jsp
在該文件頁首添加<%@ page pageEncoding="GBK"%>。
這裏對pageEncoding的賦值取決於CAS系統所管理的項目中對頁面編碼的設置。
例如，利用CAS對helper項目進行登錄驗證管理，Passport
（CAS服務端，負責對用戶進行驗證）中編碼爲“UTF-8”而helper中編碼爲“GBK”，casServiceValidationSuccess.jsp負責在CAS對用戶驗證成功後將用戶信息轉往helper/CAS/login.jsp頁面，用戶信息發送與接受處的編碼不一致，導致在login.jsp上不能獲得正確的中文信息（獲得的均爲問號）。因此應在casServiceValidationSuccess.jsp頁面上添加<%@ page pageEncoding="GBK"%>，
從而與helper/CAS/login.jsp上的頁面編碼(GBK)設置相一致。
下邊爲SetCharacterEncodingFilter代碼：
package filters;
import java.io.IOException;
import javax.servlet.*;
public class SetCharacterEncodingFilter implements Filter {
public SetCharacterEncodingFilter() {
encoding = null;
filterConfig = null;
ignore = true;
}
public void destroy() {
encoding = null;
filterConfig = null;
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if (ignore || request.getCharacterEncoding() == null) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
chain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
encoding = filterConfig.getInitParameter("encoding");
String value = filterConfig.getInitParameter("ignore");
if (value == null)
ignore = true;
else if (value.equalsIgnoreCase("true"))
ignore = true;
else if (value.equalsIgnoreCase("yes"))
ignore = true;
else
ignore = false;
}
protected String selectEncoding(ServletRequest request) {
return encoding;
}
protected String encoding;
protected FilterConfig filterConfig;
protected boolean ignore;
}