json - HttpClient 不使用带有俄语字符的 json 发送请求

Question

我制作客户端应用程序并使用 HttpClient。它完美地发送和获取带有拉丁符号的 json，但是当我尝试发送带有俄语字母的 json(具有相同的请求地址和服务器)时，它不会向服务器发送任何请求。 这是代码:

  class RestApiClientBase {

  static String _server;
  static String _ssid;
  final HttpClient _client = new HttpClient();
  static const _codec = const JsonEncoder.withIndent(" ");

  RestApiClientBase() {
    _client.badCertificateCallback =
        (X509Certificate cert, String host, int port) => true; //for self-signed cert
  }

  void setServer(String serverNew) {
    _server = serverNew;
  }

  void setSsid(String ssidNew) {
    _ssid = ssidNew;
  }

  dynamic invokePost(String method, String data) async {
    return await _client.postUrl(Uri.parse(_server + method))
        .then((HttpClientRequest request) async {
      //print('11111111111111111111111');
      request.headers.contentType
      = new ContentType("application", "json", charset: "utf-8");
      //print('22222222222222222222222');
      request.contentLength = data.length;
      //print('33333333333333333333333');
      request.write(data);
      //print('44444444444444444444444');
      return await request.close();
    })
        .then((HttpClientResponse response) async {
      if (response.statusCode == 200) {
        return response
            .transform(UTF8.decoder)
            .single;
      } else {
        String errorJson = RestApiClientBase._codec.convert(
            {
              "status": "error",
              "message": "Error code: ${response.statusCode}"
            });
        return errorJson;
      }
    }).then((String answer) async {
      var json = JSON.decode(answer);
      rState.setRState(method, json["status"], json["message"]);
      return json;
    });
  }
}
class SecurityGroupClient extends RestApiClientBase {
  dynamic getSGroups() async {
    String json = RestApiClientBase._codec.convert(
        {"ssid": RestApiClientBase._ssid});
    return await invokePost("sgroup/list", json);
  }

  dynamic createSGroup(String name, String info) async {
    String json = RestApiClientBase._codec.convert(
        {"ssid": RestApiClientBase._ssid, "name": name, "info": info});
    print(json);
    return await invokePost("sgroup/create", json);
  }
}

我收到所有消息 (111,222,333,444)，但之后我没有收到任何其他消息。 这是 json 的示例:

{
"ssid": "6a3b1d12-cd4d-4962-ae06-34d36e31ac7e",
"name": "Тестовая группа на русском",
"info": "тест"
} Server uses https.

Answer 1

发生这种情况是因为 contentLength 错误。默认情况下，内容是 UTF8 编码的。所以实际上数据长度!=字符串长度。如果您运行控制台应用程序，它将抛出异常

Content size exceeds specified contentLength. 69 bytes written while expected 38.

所以获得编码长度的最佳解决方案是:

request.contentLength = UTF8.encode(data).length;