SpringMVC-文件上传与下载

文件上传与下载

1.下载

	@RequestMapping("/testDown")
    public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException {
        //获取servletcontext对象
        ServletContext servletcontext=session.getServletContext();
        //获取服务器中文件的真实路径
         String realPath=servletcontext.getRealPath("/static/img/1.jpg");
         System.out.println(realPath);
         //创建输入流I
        InputStream is = new FileInputStream(realPath);
        //创建字节数组
        byte[] bytes =new byte[is.available()];
        //将流读到字节数组中
        is.read(bytes);
        //创建HttpHeaders对象设置响应头信息
        MultiValueMap<String,String> headers = new HttpHeaders();
        //设置要下载方式以及下载文件的名字 只有1.jpg可以修改
        headers.add("content-Disposition","attachment;filename=1.jpg");
        //设置响应状态码
        HttpStatus statuscode = HttpStatus.OK;
        //创建ResponseEntity对象
         ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, headers, statuscode);
         //关闭输入流is.close();
        return responseEntity;
    }

2.上传

2.1添加依赖
pom.xml

 <dependency>
            <groupId>commons-fileuploadgroupId>
            <artifactId>commons-fileuploadartifactId>
            <version>1.3.1version>
dependency>

2.2.配置文件上传解析器
SpringMVC配置文件

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >bean>

2.3

  @RequestMapping("/testUp")
    public String testUp(MultipartFile photo ,HttpSession session) throws IOException {
        String fileName = photo.getOriginalFilename();
         //获取上传的文件的后绿名
        String suffixName = fileName.substring(fileName.lastIndexOf("."));
        //将UUID作为文件名
        String uuid = UUID.randomUUID().toString();
        //将uuid和后缀名拼接后的结果作为最终的文件名
        fileName = uuid + suffixName;
        ServletContext servletContext=session.getServletContext();
        String photoPath=servletContext.getRealPath("photo");
        File file = new File(photoPath);
        //判断photoPath所对应路径是否存在
        if(!file.exists()) {
            //若不存在，则创建目录
            file.mkdir();
        }
        String finalPath = photoPath + File.separator + fileName;
        photo.transferTo(new File(finalPath));
        return "target";
    }