spring 上传 下載文件

1，spring配置文件添加文件上传配置

<!-- 上传文件 -->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 1GB -->
       <property name="maxUploadSize" value="" />
       <property name="defaultEncoding" value="utf-8"/>
    </bean>

2，html

 <form method="post" accept-charset="UTF-8"  th:action="${#httpServletRequest.contextPath+'/upload'}" id="multipartform" enctype="multipart/form-data"  class="form-search" role="form">
                        <input type="file" name="file" size="" id="file" /><button type="submit" id="multipart" class="btn">上传</button>
                        </form>

3，controller

     @RequestMapping(value = "/upload",method= RequestMethod.POST)
     @ResponseBody
     public String upload(HttpServletRequest request,HttpServletResponse response,@RequestParam("file") MultipartFile file) {
         if (file.isEmpty()) {
             return ResponseJSON.instance().setStatus(false).addAlertMessage("请选择导入文件！").toJSON();
         }
         String filename = file.getOriginalFilename();
         int index = filename.indexOf(".");
         String file_suffix = filename.substring(index, filename.length());
         if (!file_suffix.equals(".txt")) {
             return ResponseJSON.instance().setStatus(false).addAlertMessage("请选择txt格式文件！").toJSON();
         }
         try {
             BufferedReader reader = null;
             String usernameString = null;
             InputStreamReader isr = null;
             int line = ;
             try {
                 isr = new InputStreamReader(file.getInputStream(), "utf-8");// 考虑到编码格式
                 reader = new BufferedReader(isr);
                 while ((usernameString = reader.readLine()) != null) {
                     system.out.println(usernameString);
                     line++;
                 }

             } catch (FileNotFoundException e) {
                 // TODO Auto-generated catch block
                 logger.error("读取文件失败！", e);
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 logger.error("读取文件失败！", e);
             } finally {
                     reader.close();
                     isr.close();
                     in.close();
             }
         } catch (IOException e) {
             // TODO Auto-generated catch block
             logger.error("上传文件失败", e);
             return ResponseJSON.instance().setStatus(false).addAlertMessage("上传文件失败").toJSON();
         }
         return ResponseJSON.instance().setStatus(true).toJSON();
     }

     /**
      * 写成txt文件格式
      *
      * @param path
      * @throws IOException
      */
     @RequestMapping(value = "/load")
     public void writeTxt(HttpServletRequest request, HttpServletResponse response) throws IOException {
         response.setContentType("text/plain");
         response.setCharacterEncoding("UTF-8");
         response.setHeader("Content-disposition", "attachment;filename=result.txt");
         String name_ip = "这是一个txt文件";
         OutputStream ops = null;
         try {
             ops = response.getOutputStream();
             ops.write(name_ip.getBytes());

         } catch (IOException e) {
             // TODO Auto-generated catch block
             logger.error("写结果文件异常：", e);
         } finally {
             ops.close();
         }

     }