springmvc之文件上傳、下載

1、接收到的是圖片的流時

//上傳頭像
    @RequestMapping(value = "/uploadHeadSculpture", method = RequestMethod.POST)
    @ResponseBody
    public String uploadHeadSculpture(@RequestParam("photo") String file) {
        User user = (User) SecurityUtils.getSubject().getSession().getAttribute("curr_user");
        //獲取文件格式
        String postfix = file.split("/")[1].split(";")[0];
        //獲取圖片的Base64碼
        String str = file.split(",")[1];
        String url = "";
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // Base64解碼
            byte[] bytes = decoder.decodeBuffer(str);
            for (int i = 0; i < bytes.length; ++i) {
                // 調整異常數據
                if (bytes[i] < 0) {
                    bytes[i] += 256;
                }
            }
            long title = Calendar.getInstance().getTimeInMillis();
            //獲取系統路徑並設定文件保存的目錄
            String dir = ServiceConfigUtil.getValue("imgpath");//圖片的上傳路徑，我這里是從工程的配置文件獲取的
            String fileName = title + "." + postfix;
            // 生成jpeg圖片
            FileUtils.writeByteArrayToFile(new File(dir, fileName), bytes);
            String lookUserPhoto = ServiceConfigUtil.getValue("lookUserPhoto");//圖片的訪問路徑，我這里是從工程配置文件獲取的，可以自己定義。如果你的圖片保存在工程目錄下，可以直接用dir+fileName
            url = lookUserPhoto + fileName;//保存到數據庫的圖片訪問路徑
            /××
　　　　　　　　×保存url到數據庫
　　　　　　　××/

        } catch (Exception e) {return "no";
        }return "yes";
    }

注：接收參數file值的一個基本格式

　　"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAIAAAACACAYAAADDPmHLAAAdiUlEQVR........."

2、接收到的是file文件直接上傳

 @RequestMapping(value={"/saveOrUpdate"},method=RequestMethod.POST)
 public String saveOrUpdate(Person p, @RequestParam("photo") MultipartFile file, HttpServletRequest request) throws IOException{
     if(!file.isEmpty()){
        ServletContext sc = request.getSession().getServletContext();
         String dir = sc.getRealPath(“/upload”);    //設定文件保存的目錄
        
        String filename = file.getOriginalFilename();    //得到上傳時的文件名
        FileUtils.writeByteArrayToFile(new File(dir,filename), file.getBytes());
        
        p.setPhotoPath(“/upload/”+filename);    //設置圖片所在路徑
        
        System.out.println("upload over. "+ filename);
    }    
    ps.saveOrUpdate(p);    
    return "redirect:/person/list.action";   //重定向
}

 2.1、頁面

<form action="/saveOrUpdate" enctype="multipart/form-data" method="post">
    <input type="file" name="photo">
    <input type="submit" value="commit">
</form>

2.2、需要在springmvc配置文件中添加

<!--上傳文件-->
    <bean id="multipartResolver"
          class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="maxUploadSize" value="10000000000000"/>
        <property name="defaultEncoding" value="UTF-8"/>
    </bean>

3、文件下載

private void downFile(String filename, String realPath, HttpServletResponse response) throws IOException {
        try {
            filename = new String(filename.getBytes("ISO-8859-1"), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            log.warn("文件轉碼出現異常異常信息為：" + ExceptionUtil.print(e));
        }
        log.debug("下載的文件名：" + filename);
        log.debug("下載的文件路徑：" + realPath);
        OutputStream os = null;
        InputStream inputStream = null;
        try {
            response.setCharacterEncoding("utf-8");
            response.setContentType("multipart/form-data");
            response.setContentType("application/x-download");
            response.setHeader("Content-Disposition", "attachment;fileName="
                    + filename);
            inputStream = new FileInputStream(realPath);
            os = response.getOutputStream();
            byte[] b = new byte[1024];
            int length;
            while ((length = inputStream.read(b)) != -1) {
                os.write(b, 0, length);
            }
            os.flush();
        } catch (IOException e) {
            log.warn("下載文件出現異常，異常信息為：" + ExceptionUtil.print(e));
        } finally {
            inputStream.close();
            os.close();
        }
    }

參考：springmvc文件上傳

數據導出：java 導出excel到客戶端（本地）例子 用poi和servlet實現的