Upload file with POST method on Qt4

Question

I\'m looking for a basic code samples of how to upload files to server with HTTP POST method on Qt.

My task: I have simple Qt program and I need to

Answer 1

Use QNetworkAccessManager.

manager.post(your_qhttpnetworkrequest, your_image_qfile);

Answer 2

I see you're trying to use QHTTP and QHttpRequestHeader classes. QT documentation says those are deprecated:

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

so, as it was suggested before; I would recommend using QNetworkAccessManager for what you're trying to do

as for your original question; you still can use QHTTP to upload files; I believe actual request headers structure depends on the particular site you're trying to access. In this case tools like wireshark would be in great help. Pls, check if code below would work for you, it should upload test1.jpg file from the home folder and dump its link on the server if 302 response returned.

void MainWindow::on_pushButton_clicked()
{   
    http = new QHttp(this); // http declared as a member of MainWindow class 
    connect(http, SIGNAL(requestFinished(int,bool)), SLOT(httpRequestFinished(int, bool)));

    QString boundary = "---------------------------723690991551375881941828858";

    // action
    QByteArray data(QString("--" + boundary + "\r\n").toAscii());
    data += "Content-Disposition: form-data; name=\"action\"\r\n\r\n";
    data += "file_upload\r\n";

    // file
    data += QString("--" + boundary + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"sfile\"; filename=\"test1.jpg\"\r\n";
    data += "Content-Type: image/jpeg\r\n\r\n";

    QFile file("/home/test1.jpg");
    if (!file.open(QIODevice::ReadOnly))
        return;

    data += file.readAll();
    data += "\r\n";

    // password
    data += QString("--" + boundary + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"password\"\r\n\r\n";
    //data += "password\r\n"; // put password if needed
    data += "\r\n";

    // description
    data += QString("--" + boundary + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"description\"\r\n\r\n";
    //data += "description\r\n"; // put description if needed
    data += "\r\n";

    // agree
    data += QString("--" + boundary + "\r\n").toAscii();
    data += "Content-Disposition: form-data; name=\"agree\"\r\n\r\n";
    data += "1\r\n";

    data += QString("--" + boundary + "--\r\n").toAscii();

    QHttpRequestHeader header("POST", "/cabinet/upload/");
    header.setValue("Host", "data.cod.ru");
    header.setValue("User-Agent", "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100401 Ubuntu/9.10 (karmic) Firefox/3.5.9");
    header.setValue("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    header.setValue("Accept-Language", "en-us,en;q=0.5");
    header.setValue("Accept-Encoding", "gzip,deflate");
    header.setValue("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
    header.setValue("Keep-Alive", "300");
    header.setValue("Connection", "keep-alive");
    header.setValue("Referer", "http://data.cod.ru/");

    //multipart/form-data; boundary=---------------------------723690991551375881941828858

    header.setValue("Content-Type", "multipart/form-data; boundary=" + boundary);
    header.setValue("Content-Length", QString::number(data.length()));

    http->setHost("data.cod.ru");
    http->request(header, data);

    file.close();
}

void MainWindow::httpRequestFinished(int, bool)
{
    QHttpResponseHeader responce = http->lastResponse();
    if (responce.statusCode()==302)
    {
        qDebug() << "file accepted; get it from:";
        qDebug() << "data.cod.ru" << responce.value("Location");
    }
}

httpRequestFinished declared in the signals section of the MainWindow class

hope this helps, privet ;)

Answer 3

QPixmap pix(path);
QByteArray bytes, data;
QBuffer buffer(&bytes);
if(!buffer.open(QIODevice::WriteOnly)) {
    return;
}

pix.save(&buffer, "JPG");  

data.append("Content-Disposition: form-data; name=\"photo\"; filename=\"-\"\r\n"); data.append("Content-Type: image/jpg\r\n\r\n"); //data.append("Content-Transfer-Encoding: binary\r\n"); data.append(bytes); data.append("\r\n"); data.append("--Asrf456BGe4h\r\n");

Answer 4

Also, I found today nice code: link text

It's uploader/downloader app based on Qt4, with full set of POST headers managed by QNetworkAccessManager inside, so for beginners it will be very helpful.

Owner: stiff.ru

Committer: hoxnox