Sending a Post request with JSON and Image data

[PrakharP]

Facing the issue in sending the post request with JSON and image data
Here is the code

manager = new QNetworkAccessManager(this);
QNetworkRequest request;
QUrl url(location);
request.setUrl(url);
request.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("application/json"));
request.setRawHeader("Authorization", "Basic " + (QString("%1:%2").arg("admin").arg("admin").toLatin1()).toBase64());

/* multi part */
multiPart = new QHttpMultiPart(manager);
jsonPart = new QHttpPart();
jsonPart->setHeader(QNetworkRequest::ContentTypeHeader, QVariant("text/plain"));
jsonPart->setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"data\""));
QByteArray data = jsonData.toUtf8(); // conversion of json to byte array
qDebug() << "QByte Array data: "<< data;
jsonPart->setBody(data);
multiPart->append(*jsonPart);

imagePart = new QHttpPart();
imagePart->setHeader(QNetworkRequest::ContentTypeHeader, QVariant("image/png"));
imagePart->setHeader(QNetworkRequest::ContentDispositionHeader,
                    QVariant("form-data; name=\"file\"; filename=\"newImage.jpg\""));
file = new QFile(jpegFileLocation);
file->open(QIODevice::ReadOnly);
qDebug() << "File Open Status: " << file->isOpen();
imagePart->setBodyDevice(file);
multiPart->append(*imagePart);

QNetworkReply* reply = manager->post(request, multiPart);

QObject::connect(reply, &QNetworkReply::finished, [=](){
    if(reply->error() == QNetworkReply::NoError){
        QString contents = QString::fromUtf8(reply->readAll());
        qDebug() << "Received Data: " << contents;
    }
    else{
        QString err = reply->errorString();
        qDebug() << "Error:" <<reply->error();
        qDebug() << "Error String:" << err;
    }
    reply->deleteLater();
});

getting Error in the reply

Error: QNetworkReply::ProtocolInvalidOperationError

[ChrisW67]

@PrakharP On a quick inspection, the main request is not of type "application/json" but probably "multipart/form-data" or "multipart/mixed" , the JSON part is not "text/plain", and the PNG image has an incongruous JPG name but might be OK. Not overly surprising that the server is confused.

Study the example here more closely.

[PrakharP]

@ChrisW67 thanks, but even after making the changes, it is showing an Error like

Error: QNetworkReply::InternalServerError
Code: 500

[jsulm]

@PrakharP Then you should check the server logs to see what happens.

[PrakharP]

@ChrisW67 and @jsulm
from the server got some multipart boundary issue