我点击上传文件按钮，上传文件再将文件名以modelandview类型数据返回到前台，但是前台获取的数据为空值，后台可以打印出值，也能打印出modelmap。该项目中另一个modelandview却能返回。跟点击按钮有关吗，怎么解决呢

@RequestMapping(value="/uploadfile1")
public ModelAndView uploadfile1(@RequestParam("file") CommonsMultipartFile file,ModelMap modelmap) throws IOException{
ModelAndView modelAndView = new ModelAndView();
controller：
String fname = (new SimpleDateFormat("yyyyMMddHHmmssSSS")).format(new Date());
String fileName = file.getOriginalFilename();
String[] s=fileName.split("\.");
fname=fname+"."+s[1];
System.out.println(fname);
modelmap.put("fname",fname);
//写入本地磁盘
InputStream is = file.getInputStream();
byte[] bs = new byte[1024];
int len;
OutputStream os = new FileOutputStream(new File("D:/Software_work/Workspace/foreignServe/WebRoot/images/cona/" + fname));
while ((len = is.read(bs)) != -1) {
os.write(bs, 0, len);
}
os.close();
is.close();
return new ModelAndView("modManage",modelmap);
}
前台：

${fname}

能获取到值的controller
@RequestMapping("/gomodManage")
public ModelAndView gomodManage(ModelMap modelmap) {
    ResourceBundle res = ResourceBundle.getBundle("app");
    modelmap.put("imgPath", res.getString("imgPath"));
    System.out.println("路径"+res);
    return new ModelAndView("modManage",modelmap);
}