使用java下载网络资源

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String fileURL = "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1599655220818&di=f1fa0e2cb095632e16e0c1a8d7470ebf&imgtype=0&src=http%3A%2F%2Fa0.att.hudong.com%2F01%2F06%2F01300000329394123030066246677.jpg";
        URL url = new URL(fileURL);
        HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
        String fileName = fileURL.substring(fileURL.lastIndexOf(".") - 6);
        resp.addHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(fileName,"UTF-8"));
        InputStream inputStream = urlConnection.getInputStream();
        ServletOutputStream outputStream = resp.getOutputStream();
        byte[] bytes = new byte[1024];
        int len;
        while ((len = inputStream.read(bytes))!=-1){
            outputStream.write(bytes,0,len);
        }
        outputStream.close();
        inputStream.close();
        urlConnection.disconnect();

    }