如何处理DirectLine连接错误

问题描述

我们使用机器人框架运行机器人，并使用JS中的直线从我们的网站连接到它。我们从自定义API端点获取令牌，并将令牌存储在sessionStorage中。然后我们使用

连接到机器人

directLine = await window.WebChat.createDirectLine({
  token,conversationId,watermark: "0"
});

一切正常，但是当我将页面保持打开状态太长时间时，sessionStorage中的令牌就会过期。页面刷新或导航到其他页面会在createDirectLine方法内部导致403错误。结果导致聊天机器人无法连接，只要sessionStorage持有该令牌。这种行为对我来说并不奇怪，但是我不知道该如何处理。

我想要的只是清除sessionStorge，请求新令牌并在发生这种情况时开始新的对话。但是我不知道该怎么做。如何从createDirectLine方法获得403错误？还是有一种方法可以预先验证令牌？ 我已经尝试过在createDirectLine方法周围放置一个try / catch块，但是403错误没有出现在catch中。

谢谢！

解决方法

此解决方案仅用于解决由于令牌过期（我认为在30分钟内）之后发生的403错误。更好的解决方案是将对话ID与令牌一起存储，并使用令牌获得新的令牌。检查official bot service documentation。

// to shorten code,we store in sessionStorage as separate items.
const expirationDuration = 1000 * 60 * 30; // 30 minutes
const currentTime = new Date().getTime();
const timeTokenStored = sessionStorage.getItem("timeTokenStored") || currentTime;

// if token is stored over 30 minutes ago,ignore it and get a new one. Otherwise,use it.
if ((currentTime - timeTokenStored) > expirationDuration) {
      const res = await fetch('https://<yourTokenEndpoint>',{ method: 'POST' });
      const { token } = await res.json();}
      const currentTime = new Date().getTime();
      sessionStorage.setItem("timeTokenStored",currentTime);
      sessionStorage.setItem('token',token);
else {
  const token = sessionStorage.getItem("token")
}

在处理时，最好将其存储在localStorage中。这样，您的漫游器就会跟随用户。

,

我找到了解决方案。我们可以通过刷新令牌来检查令牌是否有效。如果刷新导致错误，则令牌不再有效。如果刷新成功，则令牌将再有效一个小时。

因此，我们在后端添加了（可重复使用的）函数，以使用https://directline.botframework.com/v3/directline/tokens/refresh刷新令牌。 然后我们更改了前端代码，以调用新的刷新功能。

前端代码：

// Gets a new token from the cloud.
async function requestToken() {
  if (!sessionStorage['webchatToken']) {
    const res = await fetch('https://' + serviceName + '.azurewebsites.net/api/token');
    // If the request was succesfull,store the token and userId.
    if (res.status == 200) {
      const jsonResult = await res.json();
      sessionStorage['webchatToken'] = jsonResult.token;
      sessionStorage['webchatUserId'] = jsonResult.userId;
      console.log(`Got token from cloud`);

      // refresh the token every 15 minutes.
      setTimeout(() => {
        refreshToken();
      },60000 * 15); // 15 minutes
    }
    // If the request was not succesfull,retry.
    else {
      console.log(`Tried to get token,but goterror ` + res.status + `. Retrying.`);
      await requestToken();
    }
  }
  // If there is already a token in storage,refresh the existing one instead of requesting a new one.
  else {
    console.log(`Got token from sessionStorage`);
    await refreshToken();
  }
}

// Refreshes an existing token so it doesn't expire.
async function refreshToken() {
  // Refresh the token if it exists in storage.
  if (sessionStorage['webchatToken']) {
    const res = await fetch('https://' + serviceName + '.azurewebsites.net/api/token/refresh?token=' + sessionStorage['webchatToken'],{
      method: 'POST'
    });
    // If refresh was succesfull we are done.
    if (res.status == 200) {
      console.log(`Refreshed token`);
    }
    // If refresh was not succesfull,clear the token from storage and request a new one. The token is probably expired.
    else {
      console.log(`Tried to refresh token,but got error ` + res.status + `. Requesting new token.`);
      sessionStorage.clear();
      await requestToken();
    }
  }
  // If there is no token in storage,request a new token.
  else {
    console.log(`Tried to refresh token,but token is not defined. Requesting new token.`);
    sessionStorage.clear();
    await requestToken();
  }
}

后端代码：

[HttpGet]
[Route("api/token")]
public async Task<ObjectResult> GetToken()
{
  HttpClient client = new HttpClient();

  HttpRequestMessage request = new HttpRequestMessage(
    HttpMethod.Post,$"https://directline.botframework.com/v3/directline/tokens/generate");
 
  request.Headers.Authorization = new AuthenticationHeaderValue("Bearer",_configuration.DirectLineKey);

  var userId = $"dl_{Guid.NewGuid()}";

  request.Content = new StringContent(
    JsonConvert.SerializeObject(new { User = new { Id = userId } }),Encoding.UTF8,"application/json");

  var response = await client.SendAsync(request);
  string token = String.Empty;
  int expiresIn = 0;

  if (response.IsSuccessStatusCode)
  {
    var body = await response.Content.ReadAsStringAsync();
    token = JsonConvert.DeserializeObject<DirectLineToken>(body).token;
    expiresIn = JsonConvert.DeserializeObject<DirectLineToken>(body).expires_in;
  }

  return Ok(new { token,userId,expiresIn });
}

[HttpPost]
[Route("api/token/refresh/")]
public async Task<ObjectResult> RefreshToken(string token)
{
  HttpClient client = new HttpClient();

  HttpRequestMessage request = new HttpRequestMessage(
    HttpMethod.Post,$"https://directline.botframework.com/v3/directline/tokens/refresh");

  request.Headers.Authorization = new AuthenticationHeaderValue("Bearer",token);


  var response = await client.SendAsync(request);
  token = String.Empty;
  int expiresIn = 0;

  if (response.IsSuccessStatusCode)
  {
    var body = await response.Content.ReadAsStringAsync();
    token = JsonConvert.DeserializeObject<DirectLineToken>(body).token;
    expiresIn = JsonConvert.DeserializeObject<DirectLineToken>(body).expires_in;
  }

  if (string.IsNullOrEmpty(token))
    return Problem("Token incorrect");

  return Ok(new { token,expiresIn });
}

我希望发布此信息可能对某人有用。