/**
  * 处理教师信息的修改
  *
  * @return
  * @throws IOException
  * @throws Exception
  */
 public String updateTDeal() throws Exception {
   init();
   if (pictureUpload() != null) {
     teacher.setPictureUrl(pictureUpload());
     if (oldPicturePath != null) { // 设置了新的图片就删除原来的图片
       File file = new File(oldPicturePath);
       if (file.exists()) {
         file.delete();
       }
     }
   }
   personService.updateTeacher(teacher);
   response.getWriter().write("<script type='text/javascript'> alert('修改教师信息成功')</script>");
   response.flushBuffer();
   response.getWriter().close();
   return NONE;
 }