http协议后端设置了Set-Cookie，前端无法接收到？

Question

后端设置了Set-Cookie:

// 给客户端回复HTTP报文
void HttpServer::HandleResponse(const string &json, int sock,const string& sessionId,const string& url)
{
    string httpResponse;
    httpResponse += "HTTP/1.1 200 OK\r\n";
    //cerr << "请求行构建完成" << endl;

    //指定内容类型json
    httpResponse += "Content-Type:application/json\r\n";
    httpResponse += "Access-Control-Allow-Origin:*\r\n";
    httpResponse += "Access-Control-Allow-Credentials:true\r\n";
    httpResponse += "Access-Control-Allow-Headers:Set-Cookie\r\n";
    //正文部分的长度/字节数
    httpResponse += "Content-Length:";
    int length = (int)json.size();
    httpResponse += std::to_string(length); 
    httpResponse += "\r\n";
    Json::Value root;
    Json::Reader reader;
    reader.parse(json,root);
    cerr << url << endl;
    cerr << sessionId.empty() << endl;
    cerr << root["userId"] << endl;
    if(sessionId.empty()&& url == "/login" && root["status"].asString()=="true")
    {
        
       string newSessionId =  generateSessionId();
       httpResponse += ("Set-Cookie:SessionId=" + newSessionId + "; Path=/; HttpOnly\r\n");
    }
    httpResponse += "\r\n";
    httpResponse += json;
    ssize_t s = send(sock,httpResponse.c_str(),httpResponse.size(),0);
    cerr << httpResponse << endl;
}

打印出来的response报文也是有set-cookie的

但是前端vue这里怎么也接收不到

 http.post("/login",this.loginForm)
       .then(response=>
        {
          console.log(response)
          if(response.data.status === "true")
          {
              // 从响应头中提取 sessionId
               const sessionId = response.headers['Set-Cookie'].split(';')[0].split('=')[1];
               console.log(sessionId)
               localStorage.setItem('sessionId', sessionId);
               this.$router.push("/personalCenter");
          }
          else{
            alert("用户名或密码错误，请重试")
          }
        }
        )
        .catch(error=>{
          alert("网络异常，请重试")
        }
      )

根本没有这个headers

我也允许第三方cookie了，跨域也允许了，httpOnly也删过了也没用，怎么办？求大佬解惑

......

Answer 1

不是所有的 HTTP Header 在前端代码中都可以访问到，Set-Cookie 就是一个前端代码无法访问的 HTTP Header

这些 Header 被浏览器提供给前端代码访问前已经被滤除。浏览器收到 Set-Cookie 响应头后会修改对应的 Cookie，你可以访问修改后的 cookie

Answer 2

你的问题在于这个