QNetworkReply和301重定向

Question

我有一个webviewer，只希望它只能够访问我们的webapps，为此我已经放置了一个php头，我在我的Qt应用程序中寻找。这工作正常，但有一个例外，那是301永久移动的状态代码。现代浏览器会自动重定向您，但会在http请求的末尾添加“/”。

当输入我们的网络应用程序的URL时，它当前需要尾部斜线能够检测标题，但是我希望它也能够在该标题处得到，即使它们没有放置尾部斜线。

这是我目前的检索标题方法：

QNetworkAccessManager *manager = new QNetworkAccessManager(this); 
    QNetworkRequest request; 
    request.setUrl(url); 
    connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(onFinished(QNetworkReply*))); 

    request.setRawHeader("User-Agent", "CytoViewer 1.0"); 
    request.setHeader(QNetworkRequest::ContentTypeHeader,"application/CytoViewer"); 
    QNetworkReply *reply = manager->get(request); 
    reply->ignoreSslErrors(); 
    QEventLoop loop; 

    connect(reply, SIGNAL(finished()), &loop, SLOT(quit())); 
    loop.exec(); 
    qDebug() << "QLoop reply all: " << reply->readAll(); 
    qDebug() << "QLoop: " << reply->rawHeader("Cyto-Study-Manager"); 
    if(reply->rawHeader("OurWebApp") == "1"){ 
     //Header exists?(QEventLoop finish) Set arg[1]"url 'Found prouct: product header'" 
     product = reply->rawHeader("Product"); 
     return true; 
    } else { 
     //Header doen't exist? Graceful error - not a valid PI product 
     return false; 
    } 

为了解决击中301首先我送两个网络请求的问题，第一个打网址进入，并检查了301，如果有一个301状态码，它通过reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();方法得到建议的URL，如果没有状态码，则返回该URL，否则它仅仅返回用户输入的前一个URL，然后发送另一个网络请求来检查标题。

我送出去检查状态码第一个请求：

QUrl MainWindow::networkRequest(QUrl checkUrl){ 
    qDebug() << "checkURL: " << checkUrl; 
    // 
    QNetworkAccessManager *manager = new QNetworkAccessManager(this); 
    QNetworkRequest request; 
    request.setUrl(checkUrl); 
    request.setRawHeader("User-Agent", "CytoViewer 1.0"); 
    request.setHeader(QNetworkRequest::ContentTypeHeader,"application/CytoViewer"); 
    QNetworkReply *reply = manager->get(request); 
    reply->ignoreSslErrors(); 
    QEventLoop checkLoop; 
    connect(reply, SIGNAL(finished()), &checkLoop, SLOT(quit())); 
    checkLoop.exec(); 
    //Check status code 
    if (reply->error() == QNetworkReply::NoError) { 
     int statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(); 
     if(statusCode == 301) { 
      QUrl redirectUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl(); 
      return redirectUrl; 
     }else { 
      return checkUrl; 
     } 

    } 
} 

长话短说，我送两个网络请求，1）要检查301 2）要检查我们的应用程序标题。

有没有办法在一个请求中做到这一点？我是否缺少自动执行此重定向的方法？

问候

弥敦道

Answer 1

显然没有。

有上http://developer.nokia.com/community/wiki/Handling_an_HTTP_redirect_with_QNetworkAccessManager官方HOWTO条目（死链接，不幸）

提取从上面的链接：

void QNAMRedirect::replyFinished(QNetworkReply* reply) { 
    /* 
    * Reply is finished! 
    * We'll ask for the reply about the Redirection attribute 
    * http://doc.trolltech.com/qnetworkrequest.html#Attribute-enum 
    */ 
    QVariant possibleRedirectUrl = 
      reply->attribute(QNetworkRequest::RedirectionTargetAttribute); 

    /* We'll deduct if the redirection is valid in the redirectUrl function */ 
    _urlRedirectedTo = this->redirectUrl(possibleRedirectUrl.toUrl(), 
             _urlRedirectedTo); 

    /* If the URL is not empty, we're being redirected. */ 
    if(!_urlRedirectedTo.isEmpty()) { 
     QString text = QString("QNAMRedirect::replyFinished: Redirected to ") 
           .append(_urlRedirectedTo.toString()); 
     this->_textContainer->setText(text); 

     /* We'll do another request to the redirection url. */ 
     this->_qnam->get(QNetworkRequest(_urlRedirectedTo)); 
    } 
    else { 
     /* 
     * We weren't redirected anymore 
     * so we arrived to the final destination... 
     */ 
     QString text = QString("QNAMRedirect::replyFinished: Arrived to ") 
           .append(reply->url().toString()); 
     this->_textContainer->setText(text); 
     /* ...so this can be cleared. */ 
     _urlRedirectedTo.clear(); 
    } 
    /* Clean up. */ 
    reply->deleteLater(); 
} 

QUrl QNAMRedirect::redirectUrl(const QUrl& possibleRedirectUrl, 
           const QUrl& oldRedirectUrl) const { 
    QUrl redirectUrl; 
    /* 
    * Check if the URL is empty and 
    * that we aren't being fooled into a infinite redirect loop. 
    * We could also keep track of how many redirects we have been to 
    * and set a limit to it, but we'll leave that to you. 
    */ 
    if(!possibleRedirectUrl.isEmpty() && 
     possibleRedirectUrl != oldRedirectUrl) { 
     redirectUrl = possibleRedirectUrl; 
    } 
    return redirectUrl; 
} 

Answer 2

这是一个有点老，但自动重定向的支持也刚刚加入的Qt 5.6。看看这个QNetworkRequest::FollowRedirectsAttribute（http://doc.qt.io/qt-5/qnetworkrequest.html）。