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 select any image file from the local host and upload it to the server. The selection part and GUI is simple and I have already done it, but with POST uploading I’m confused. In addition I have to say, that there is no authorization to upload file.

If someone already looking this topic?

PS: the reason why I’m asking and not coding my self is time, I need to get this method quick.

Thank you, all success solutions from my side will be posted here for others.

ADDED: Here is my code, that doesn’t work yet. Upload site located here.

void    CDialog::on_uploadButton_clicked() {

    QFileInfo fileInfo(absPathLineEdit->text());

    if (!fileInfo.exists()) {
        QMessageBox::information(this, 
            tr("Information"), 
            tr("File doesn't exists! Please, select another image."));
        return;
    }

    file = new QFile(fileInfo.filePath());
    if (!file->open(QIODevice::ReadOnly)) {
        QMessageBox::information(this,
            tr("Information"),
            tr("Unable to open file for reading!"));
        return;
    }

    QString host = "http://data.cod.ru";

    QUrl url(host);

    QHttp::ConnectionMode mode = QHttp::ConnectionModeHttp;
    http->setHost(url.host(), mode, (url.port() == -1) ? 80 : url.port());

    QHttpRequestHeader header("POST", "/", 1, 1);
    header.setValue("Host", "data.cod.ru");
    header.setValue("Content-type", "multipart/form-data, boundary=AaB03x");
    header.setValue("Cache-Control", "no-cache");
    header.setValue("Accept", "*/*");

    QByteArray bytes(fileInfo.filePath().toUtf8());
    QByteArray totalBytes;
    totalBytes.append("--AaB03x\r\n");
    totalBytes.append("Content-Disposition: form-data; name=\"email\"\r\n");
    totalBytes.append("\r\n");
    totalBytes.append("[e-mail]\r\n");
    totalBytes.append("--AaB03x\r\n");
    totalBytes.append("Content-Disposition: form-data; name=\"photo\"; filename=\"" + bytes+ "\"\r\n");
    totalBytes.append("Content-Transfer-Encoding: binary\r\n\r\n");
    totalBytes.append(file->readAll());
    totalBytes.append("\r\n");
    totalBytes.append("--AaB03x--");

    header.setContentLength(totalBytes.length());

    httpRequestAborted = false;
    httpGetId = http->request(header, totalBytes);

    file->close();
}

and read answer function below:

void    CDialog::httpRequestFinished(int requestId, bool error) {

    if (requestId != httpGetId)
        return;

    if (httpRequestAborted) {
        if (file) {
            file->close();
//          file->remove();
//          delete file;
            file = 0;
        }
        return;
    }

    if (requestId != httpGetId)
        return;

    file->close();

    if (error) {
//      file->remove();
        QMessageBox::information(this, tr("HTTP"),
            tr("Download failed: %1.")
            .arg(http->errorString()));
    } else {
        QByteArray data = http->readAll();
        QFile *dataFile = new QFile("answer.txt");
        dataFile->open(QIODevice::WriteOnly | QIODevice::Text);
        dataFile->write(data);
        dataFile->flush();
        dataFile->close();
    }

//  delete file;
    file = 0;
}

Answer 1

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