How to solve this dio library error? Flutter/Dart-CodePudding

Hello there i am trying to download a pdf file with dio library but in the end i get this errror:

I/flutter (19900): 100%
I/flutter (19900): connection: keep-alive
I/flutter (19900): last-modified: Mon, 17 Oct 2022 10:17:34 GMT
I/flutter (19900): cache-control: no-cache, no-store, max-age=0, must-revalidate
I/flutter (19900): date: Fri, 21 Oct 2022 07:39:15 GMT
I/flutter (19900): vary: Origin
I/flutter (19900): vary: Access-Control-Request-Method
I/flutter (19900): vary: Access-Control-Request-Headers
I/flutter (19900): content-type: text/html;charset=UTF-8
I/flutter (19900): pragma: no-cache
I/flutter (19900): x-xss-protection: 1; mode=block
I/flutter (19900): content-language: en
I/flutter (19900): server: nginx/1.15.12
I/flutter (19900): accept-ranges: bytes
I/flutter (19900): content-length: 6425
I/flutter (19900): x-frame-options: DENY
I/flutter (19900): x-content-type-options: nosniff
I/flutter (19900): expires: 0
I/flutter (19900): FileSystemException: Cannot open file, path = '/data/user/0/com.iccs.electromobilityapp/cache' (OS Error: Is a directory, errno = 21)

Here is my code:

Future download2(Dio dio, String url, String savePath) async {
    Directory tempDir = await getTemporaryDirectory();
    tempPath = tempDir.path;
    String? token = await this.widget.appController.storage.read(key: "token");
    Map<String, String> headers = {
      "Content-Type": "application/json",
      "Accept": "application/json",
      "Authorization": "Bearer "   (token ?? ""),
    };
    try {
      Response response = await dio.get(
        url,
        onReceiveProgress: showDownloadProgress,
        //Received data with List<int>
        options: Options(
          headers: headers,
            responseType: ResponseType.bytes,
            followRedirects: false,
            validateStatus: (status) {
              return status! < 500;
            }),
      );
      print(response.headers);
      new File('$tempPath/file.xlsx').create(recursive: true);
      File file = File(tempPath);
      var raf = file.openSync(mode: FileMode.write);
      // response.data is List<int> type
      raf.writeFromSync(response.data);
      await raf.close();
    } catch (e) {
      print(e);
    }
  }

CodePudding user response：

I've written a simple function for you just pass a url and filename as an argument

  downloadedFile({required String url, required String filename}) async {
    var downloadsDirectoryPath = await getTemporaryDirectory()
    final File file = File("/${downloadsDirectoryPath!.path}/$filename");
    final response = await Dio().get(url, onReceiveProgress: (received, total) {
    },
        options: Options(
          responseType: ResponseType.bytes,
          followRedirects: false,
          receiveTimeout: 0,
        ));
    final raf = file.openSync(mode: FileMode.write);
    raf.writeFromSync(response.data);
    await raf.close();
    return file;
  }

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