url轉變爲 MultipartFile對象

/** * url轉變爲 MultipartFile對象 * @param url * @param fileName * @return * @throws Exception */private static MultipartFile createFileItem(String url, String fileName) throws Exception{    FileItem item = null;    try {        HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();        conn.setReadTimeout(30000);        conn.setConnectTimeout(30000);        //設置應用程序要從網絡鏈接讀取數據        conn.setDoInput(true);        conn.setRequestMethod("GET");        if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {            InputStream is = conn.getInputStream();            FileItemFactory factory = new DiskFileItemFactory(16, null);            String textFieldName = "uploadfile";            item = factory.createItem(textFieldName, ContentType.APPLICATION_OCTET_STREAM.toString(), false, fileName);            OutputStream os = item.getOutputStream();            int bytesRead = 0;            byte[] buffer = new byte[8192];            while ((bytesRead = is.read(buffer, 0, 8192)) != -1) {                os.write(buffer, 0, bytesRead);            }            os.close();            is.close();        }    } catch (IOException e) {        throw new RuntimeException("文件下載失敗", e);    }    return new CommonsMultipartFile(item);}