自己书写通用jdbc文件上传下载方法

「爱情、让人受尽委屈。」 2022-06-01 12:23 186阅读 0赞

文件上传有两种情况  
①直接将文件存入数据库

/**通用文件上传(支持所有文件--直接写入数据库) * @throws FileUploadException * @throws IOException * @throws SQLException **/
        public Object commonFileUploadLoadInOracleBlob(HttpServletRequest request,
                HttpServletResponse response, Connection conn)
                throws FileUploadException, IOException, SQLException {
            DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
            ServletFileUpload servletFileUpload = new ServletFileUpload(
                    diskFileItemFactory);
            request.setCharacterEncoding("UTF-8");
            response.setCharacterEncoding("UTF-8");
            List<FileItem> fileItemList = servletFileUpload.parseRequest(request);
            InputStream inputStream = null;
            if (fileItemList != null) {
                for (FileItem fileItem : fileItemList) {
                    if (fileItem.isFormField()) {
                        String name = fileItem.getFieldName();
                        if (name.equals("first_clum")) {
       // 非文件表单元素1
    
                        } else if (name.equals("second_clum")) {
       // 非文件表单元素2
    
                        }
                    }
                    if (!fileItem.isFormField()) {
                        inputStream = fileItem.getInputStream();
                    }
                }
            }
            // 开始执行插入操作
            String insettrTmgJgDlDetlSql = "insert into TR_TMG_PDA_BLOB "
                    + "(FILE_BLOB,file_name) values(?,?)";
            PreparedStatement prep = conn.prepareStatement(insettrTmgJgDlDetlSql);
            prep.setBinaryStream(1, inputStream);
            prep.setString(2, "fileName.jpg");
            prep.addBatch();
            prep.executeBatch();
            prep.close();
            return null;
        }

② 将文件存入服务器

/**通用文件上传(文件上传到服务器) * @throws Exception **/
        public void commonFileUploadToService(HttpServletRequest request,
                HttpServletResponse response, Connection conn, String uploadPath)
                throws Exception {
            DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
            ServletFileUpload servletFileUpload = new ServletFileUpload(
                    diskFileItemFactory);
            request.setCharacterEncoding("UTF-8");
            response.setCharacterEncoding("UTF-8");
            List<FileItem> fileItemList = servletFileUpload.parseRequest(request);
            File uploadedFile = null;
            if (fileItemList != null) {
                for (FileItem fileItem : fileItemList) {
                    if (fileItem.isFormField()) {
                        String name = fileItem.getFieldName();
                        if (name.equals("first_clum")) {
       // 非文件表单元素1
    
                        } else if (name.equals("second_clum")) {
       // 非文件表单元素2
    
                        }
                    }
                    if (!fileItem.isFormField()) {
                        String fileName = fileItem.getFieldName();
                        // 创建一个抽象路径，如果不存在的话就创建一个文件夹。
                        File dir = new File(uploadPath);
                        if (!dir.exists()) {
                            dir.mkdir();
                        }
                        String newFileFullName = uploadPath + fileName;
                        uploadedFile = new File(newFileFullName);
                        fileItem.write(uploadedFile);
                    }
                }
            }
        }

文件下载代码如下

/**通用文件下载(直接下载到浏览器) * @throws SQLException * @throws IOException **/
        public void commonFileDownloadFromOracleBlob(HttpServletRequest request,
                HttpServletResponse response, Connection conn) throws SQLException,
                IOException {
            String sql = "";// 自己填写的sql
            PreparedStatement prep = conn.prepareStatement(sql);
            ResultSet rs = prep.executeQuery(sql);
            while (rs.next()) {
                String fileName = "";// 文件的名字
                oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("file_blob");
                response.setContentType("application/octet-stream");
                response.setHeader("Content-Disposition", "attachment;fileName=\""
                        + new String(fileName.getBytes("UTF-8"), "ISO8859-1")
                        + "\"");
                response.addHeader("extra_key_Name", fileName);
                response.setHeader("Connection", "close");
                response.setHeader("Content-Length", "");
                response.addIntHeader("response_status", 2001);
                response.addHeader("response_message", "ok");
                addResponseHeader(response, 2001, "ok");
                OutputStream outputStream = response.getOutputStream();
                InputStream inputStream = blob.getBinaryStream();
                byte[] buffer = new byte[1024 * 1024];
                int i = -1;
                while ((i = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, i);
                }
                inputStream.close();
                outputStream.flush();
                outputStream.close();
            }
        }