springMVC后台的值无法通过ModelAndView的addObject传到前台

我将studentList放入request作用域中jsp可以访问,为什么通过ModelAndView的addObject方法放入后,前台就无法访问。

后台方法:
@RequestMapping("/studentList")
public ModelAndView studentList(HttpServletRequest request) throws Exception{
ModelAndView mav = new ModelAndView("studentList");
// List studentList = iStudentService.queryAllStudent();
// System.out.println(studentList.size());
// request.setAttribute("studentList", studentList);
mav.addObject("studentList", iStudentService.queryAllStudent());
mav.addObject("xx", "xx");
// mav.addObject("studentList",studentList);
return mav;
}
前台代码

${xx}











/c:forEach

按照标准用法的话应该是没问题
内部其实把model 通过request.setAttribute(modelName, modelValue); 放入的
[code="java"] protected void exposeModelAsRequestAttributes(Map model, HttpServletRequest request) throws Exception {
for (Map.Entry entry : model.entrySet()) {
String modelName = entry.getKey();
Object modelValue = entry.getValue();
if (modelValue != null) {
request.setAttribute(modelName, modelValue);
if (logger.isDebugEnabled()) {
logger.debug("Added model object '" + modelName + "' of type [" + modelValue.getClass().getName() +
"] to request in view with name '" + getBeanName() + "'");
}
}
else {
request.removeAttribute(modelName);
if (logger.isDebugEnabled()) {
logger.debug("Removed model object '" + modelName +
"' from request in view with name '" + getBeanName() + "'");
}
}
}
}[/code]

一个可能是你实现了HandlerInterceptor并实现了：
void postHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, java.lang.Object o, org.springframework.web.servlet.ModelAndView modelAndView) throws java.lang.Exception;

在此处修改了modelAndView

如果方便可以贴全代码，或者把代码站内信我