SSM（spring+springMVC+mybatis）文件上傳下載

-上傳
–上傳前臺代碼

<input type="file" name="doc">

–後臺代碼

@RequestMapping("upload")
    public String upload(Integer bid, MultipartFile doc, Model model) {
        BankBean bank = new BankBean();
        if (!doc.isEmpty()) {
            // 獲取路徑
            String filePath = "D:\\img\\upload\\";
            String originalFilename = doc.getOriginalFilename();
            // UUID隨機重命名
            String newFileName = (UUID.randomUUID() + originalFilename
                    .substring(originalFilename.indexOf("."))).replace("-", "");
            // 新文件
            File file = new File(filePath + newFileName);
            // 將文件寫入磁盤
            try {
                doc.transferTo(file);
                // 將圖片名字寫入實體類
                bank = bankService.getBankByBid(bid);
                bank.setFileName(newFileName);
            } catch (IllegalStateException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        } else {
            System.out.println("文件爲空");
            model.addAttribute("bid", bid);
            // 返回上傳頁面
            return "upload";
        }
        // 將圖片名字寫入數據庫
        bankService.updateBank(bank);
        // 返回列表頁面查看
        return "redirect:getBankList.action";
    }

–前臺展示圖片代碼
—-tomcat展示絕對路徑時需要配置如下
在tomcat文件中conf文件夾下server.xml文件中的Host雙標籤中配置虛擬路徑

<Host>
    <Context path="/upload" docBase="D:\img\upload\"  reloadable="true"></Context>
</Host>

–展示/下載前臺

<c:if test="${b.fileName != null && b.fileName != '' }">
                        <a href="downLoad.action?fileName=${b.fileName }">
                            <img width="120px" height="80px" src="/upload/${b.fileName }">
                            </a>
</c:if>

–下載後臺代碼

@RequestMapping("downLoad")
    public ResponseEntity<byte[]> download(String fileName) throws IOException {
        String filePath = "D:\\img\\upload\\";
        File file = new File(filePath + fileName);
        // 處理顯示中文文件名的問題
        String newFilename = new String(fileName.getBytes("UTF-8"),
                "iso-8859-1");
        // 設置請求頭內容,告訴瀏覽器代開下載窗口
        HttpHeaders headers = new HttpHeaders();
        headers.setContentDispositionFormData("attachment", newFilename);
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
                headers, HttpStatus.CREATED);
    }