mongodb文件上传和读取文件

@Autowired
	private GridFsOperations operations;

/**
	 * 保存图片
	 * 
	 * @param file
	 * @param fileName
	 * @throws IOException
	 */
	private void saveGridFSImage(MultipartFile file, String fileName) throws IOException {
		operations.store(file.getInputStream(), fileName);
	}

	/**
	 * 删除图片
	 * 
	 * @param filename
	 */
	private void delImage(String fileName) {

		operations.delete(new Query(Criteria.where("filename").is(fileName)));
	}

	/**
	 * 判断照片会否存在
	 * 
	 * @param filename
	 * @return
	 */
	private boolean hashNextImg(String fileName) {
		GridFSFindIterable result = operations.find(new Query(Criteria.where("filename").is(fileName)));
		return result.iterator().hasNext();
	}

	/**
	 * 根据name查找图片
	 * 
	 * @param fileName
	 * @return
	 */
	private GridFsResource getImgInput(String fileName) {
		return operations.getResource(fileName);

	}