QNetworkReply和301重定向

时间:2013-02-11 09:33:44

标签: c++ qt qnetworkaccessmanager

我有一个webviewer,只希望它只能访问我们的webapps,为了达到这个目的,我已经在我的Qt App中找到了一个php标题。这样可以正常工作但有一个例外,那就是301永久移动状态代码。现代浏览器会自动重定向您,但在http请求的末尾添加“/”。

当输入我们的网络应用程序的URL时,它当前需要尾部斜杠才能检测到标题,但我希望它也能获得该标题,即使它们没有放置斜杠。

这是我当前检索标题的方法:

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;
    }

要解决首先点击301的问题,我发送两个网络请求,第一个点击输入的网址并检查301是否有301状态代码通过reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();获得建议的网址如果没有状态代码,则返回该URL,然后返回用户输入的先前URL,然后发送另一个网络请求以检查标题。

我发出第一个请求以检查状态代码:

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,我发送两个网络请求,1)检查301 2)检查我们的应用标题。

有没有在一个请求中执行此操作?我错过了一个自动执行此重定向的方法吗?

此致

2 个答案:

答案 0 :(得分:18)

自动重定向支持已添加到Qt 5.6(private in[][] pixels;)。

Check this out

答案 1 :(得分:11)

显然没有。

http://developer.nokia.com/community/wiki/Handling_an_HTTP_redirect_with_QNetworkAccessManager上有正式的HOWTO条目(不幸的是死链接)

从上面的链接中提取:

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;
}