java web 中上传文件和下载文件代码片段

待我称王封你为后i 2022-07-11 09:29 156阅读 0赞

/** * Purpose：上传文档 * * @param req * @param fileTitle * @param fileType * @param fileDesc * @return */
        @RequestMapping("upload")
        public ModelAndView upload(HttpServletRequest req, String fileType, String fileDesc, String share) {
            UserAllInfo userAll = (UserAllInfo) req.getSession().getAttribute("userAll");
            ModelAndView mav = new ModelAndView();
            // 获取文件的大小
            String fileSize = "";
            int length = req.getContentLength();
            //转换成KB
            double len1 = (double) (Math.round((length / 1024) * 100)) / 100;
            //转换成MB
            double len2 = (double) (Math.round((len1 / 1024) * 100)) / 100;
            if (len2 > 1) {
                fileSize = String.valueOf(len2) + "MB";
            } else {
                fileSize = String.valueOf(len1) + "KB";
            }
            //将请求转换成处理文件的请求
            MultipartRequest mreq = (MultipartRequest) req;
            //文件上传专用类
            MultipartFile mfile = mreq.getFile("uploadFile");
    
            // 得到上下文路径
            String root = req.getSession().getServletContext().getRealPath("/");
            File dir = new File(root);
            // 获取文件名和文件的mime类型
            String str = mfile.getOriginalFilename();
            String[] st = str.split("\\.");
    
            File savedFile = null;
            try {
                //在指定目录中创建一个新的空文件，文件名称加前缀"upload_"
                savedFile = File.createTempFile("upload_", mfile.getOriginalFilename(), dir);
                //将缓冲区的内容复制到新创建的文件中
                FileCopyUtils.copy(mfile.getInputStream(), new FileOutputStream(savedFile));
            } catch (Exception e) {
                e.printStackTrace();
            }
            String path = savedFile.getPath();
    
            // 将文件的信息封装在对象中
            FileInfo file = new FileInfo();
            if (userAll != null) {
                file.setUploadPersonId(userAll.getUser().getUserId());
            } else {
                mav.setViewName("login");
                return mav;
            }
            file.setFileName(st[0]);
            file.setFilePath(path);
            Date date = new Date();
            file.setUploadDate(date);
            file.setFileSize(fileSize);
            file.setFileType(fileType);
            file.setFileForm(st[1]);
            if ("superman".equals(userAll.getUser().getUserNumber())) {
                file.setFileShare("Y");
                file.setCheckFlag("Y");
            } else {
                file.setFileShare(share);
                file.setCheckFlag("N");
            }
            file.setDeleteFlag("N");
            file.setDownloadTimes(0);
            // 保存文件的信息
            boolean bool = fileSer.saveFile(file);
            String userNumber = userAll.getUser().getUserNumber();
            //设置跳转界面
            mav.setViewName("jsp/person/upload");
            logSer.saveLog("用户\"" + userNumber + "\"上传文件\"" + file.getFileName() + "\"");
            mav.getModel().put("bool", bool);
            return mav;
        }
    
        /** * Purpose：下载文档 * * @param fileId 文件id * @return */
        @RequestMapping("download")
        public void download(Integer fileId, HttpServletResponse resp) {
            FileInfo file = new FileInfo();
            //通过文件id获取文件的基本信息
            file = fileSer.getFileById(fileId);
    
            // 根据文件后缀名设置文件的mime类型
            String mime = "application/";
            switch (file.getFileForm()) {
            case "doc":
                mime = mime + "msword";
                break;
            case "docx":
                mime = mime + "msword";
                break;
            case "pdf":
                mime = mime + "pdf";
                break;
            case "xls":
                mime = mime + "vnd.ms-excel";
            case "ppt":
                mime = mime + "vnd.ms-powerpoint";
                break;
            case "txt":
                mime = "text/plain";
                break;
            default:
                break;
            }
            resp.setContentType(mime);
            String fileName = file.getFileName();
            String name = "";
            try {
                // 将文件名使用utf-8编码格式编码，使其中的中文字符可以正常显示
                name = URLEncoder.encode(fileName, "utf-8");
            } catch (UnsupportedEncodingException e1) {
                e1.printStackTrace();
            }
    
            // 弹框选择保存路径
            resp.setHeader("content-disposition", "attachment;filename=" + name + "." + file.getFileForm()
                    + ";filename*=utf-8''" + name + "." + file.getFileForm());
    
            String filePath = file.getFilePath();
            InputStream is = null;
            OutputStream os = null;
            try {
                is = new BufferedInputStream(new FileInputStream(filePath));
                os = new BufferedOutputStream(resp.getOutputStream());
                byte[] buff = new byte[1024];
                @SuppressWarnings("unused")
                int count;
                while ((count = is.read(buff)) != -1) {
                    os.write(buff);
                }
                //修改下载次数
                fileSer.update(fileId);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                //最后，要记得关闭输入流和输出流
                if (is != null) {
                    try {
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if (os != null) {
                    try {
                        os.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }