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="1073741824" />
       <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="5" 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 = 1;
            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();
        }

    }