Java通过网络图片之地址，下载到服务器

@RequestMapping("/downloadTableQrcode")
    public String downloadTableQrcode(HttpServletRequest request, HttpServletResponse response, @RequestParam String name, @RequestParam String url) throws Exception {
        try {
            response.setContentType("application/zip");
            String fileName = new String(name.getBytes(), "ISO8859-1"); //正确,不发生乱码
            response.setHeader("Content-Disposition", "attachment; filename=" + fileName + ".jpg");
            javax.servlet.ServletOutputStream out = response.getOutputStream();
            downloadPicture(url, request.getSession().getServletContext().getRealPath("/") + "downloadTableQrcode.jpg");
            File file = null;
            file = new File(request.getSession().getServletContext().getRealPath("/") + "downloadTableQrcode.jpg");
            InputStream inputStream = new FileInputStream(file);
            int b = 0;
            byte[] buffer = new byte[1000000];
            while (b != -1) {
                b = inputStream.read(buffer);
                if (b != -1) out.write(buffer, 0, b);
            }
            inputStream.close();
            out.close();
            out.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
        }
            return "https://linliny.com:8443/superllny/downloadTableQrcode.jpg";
    }

    //链接url下载图片
    public static void downloadPicture(String urlList, String path) {
        log.info("path==================="+path);
        URL url = null;
        try {
            url = new URL(urlList);
            DataInputStream dataInputStream = new DataInputStream(url.openStream());

            FileOutputStream fileOutputStream = new FileOutputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();

            byte[] buffer = new byte[1024];
            int length;

            while ((length = dataInputStream.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
            fileOutputStream.write(output.toByteArray());
            dataInputStream.close();
            fileOutputStream.close();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }