Spring MVC中执行操作后, 刷新页面会重复操作(已解决)

原来的代码如下：

@RequestMapping("/content/update.do")
	public String update(Integer id, String title, String content,
						 @RequestParam MultipartFile image,
						 HttpServletRequest request,
						 HttpServletResponse response,
						 ModelMap model) throws Exception {

		myContentMng.deleteImageOnServer(id);

		CmsSite site = CmsUtils.getSite(request);
		String contextPath = request.getContextPath();
		String originalFileName = image.getOriginalFilename();
		String extension = FilenameUtils.getExtension(originalFileName).toLowerCase(Locale.ENGLISH);
		String fileUrl = fileRepository.storeByExt(site.getUploadPath(), extension, image);
		cmsUserMng.updateUploadSize(CmsUtils.getUserId(request), Integer.parseInt(String.valueOf(image.getSize() / 1024)));
		fileUrl = contextPath + fileUrl;
		MyContent myContent = myContentMng.getById(id);
		myContent.setTitle(title);
		myContent.setContent(content);
		myContent.setImgPath(fileUrl);
		myCont