public Object updatefile1(@Param("upload1") TempFile f,@Param("currdate") String currdate,HttpSession session) throws IOException 
    {
        String returnstr="";
        InputStream in;
         try {
             in = f.getInputStream();
         } catch (IOException ex) {
             Logger.getLogger(zwdaAction.class.getName()).log(Level.SEVERE, null, ex);
             return "错误:读取文件错误，"+ex;
         }
        @SuppressWarnings("UnusedAssignment")
         List<ktgdzjqd> ktgDzjqd=null;
         
             dao.clear(ktgdzjqd.class,Cnd.where("drsj","=", currdate));   
            SimpleDateFormat currdate1=new SimpleDateFormat("yyyy-MM-dd");//小写的mm表示的是分钟  
    try
      {
          returnstr="文件导入数据库成功";  
          ktgDzjqd = J4E.fromExcel(in, ktgdzjqd.class,null);
            
           for(int count=0;count<=ktgDzjqd.size()/1000;count++)
           {
               dao.fastInsert(ktgDzjqd.subList(count*1000, (count+1)*1000));                   
           }
              dao.update(ktgdzjqd.class,Chain.make("drsj",currdate1.parse(currdate)),Cnd.where("drsj","is",null));
      }
    catch(ParseException ex)
    {
      returnstr="错误:文件选择错误或其他错误";  
    }
    finally
    {
           in.close();
    }         
               
      return returnstr;
    }