关于spring-mvc:SpringMVC实现下载功能

@RequestMapping("/test/down")    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实在门路        String realPath = servletContext.getRealPath("/static/img/123.jpg");        //创立输出流        InputStream is = new FileInputStream(realPath);         //创立字节数组        byte[] bytes = new byte[is.available()];        //将流读到字节数组中        is.read(bytes);        //创立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        headers.add("Content-Disposition","attachment;filename=1.jpg");        //设置响应状态码        HttpStatus statusCode = HttpStatus.OK;        //创立ResponseEntity对象        ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, headers,statusCode);        //敞开输出流        is.close();        return responseEntity;    }