HTTP

Pranit Patil

Any One working on Http in Qt application i need a help ?
how to send data on server using http protocol

jazzycamel

@Pranit-Patil The QNetwork module, specifically the QNetworkAccessManager and the associated QNetworkRequest and QNetwork reply classes are what you need.

Pranit Patil

I am trying to send following data on "https://dev.datoms.io/api/trade/initialization/create_device"

Data:
//POST /api/trade/initialization/create_device HTTP/1.1
//Host: dev.datoms.io
//Cache-Control: no-cache
//Postman-Token: 2f521ea3-8688-4fd2-b8f5-0fc7f3df62ba

Real data {"user_token":"Ej14qoqnm9PxZJWXXHPIzX8L2owzQuIPHA0QewilGs8fzScwp6XoPnsQ4KUb71iv","qr_code":"QG0Z9Q5J","circuit_version":"","device_type":1}

if i send data successfully i will get response from server .
im trying to implement but not getting.
Thank You.

Prince_0912

Hi @Pranit-Patil
For HTTP in Qt there is QtNetwork module. for that you have to inlcude
QT += network in .pro file.

after this you can add
#include <QtNetwork> in your file.

Then you can use functionalities of QtNetwork.

Hierarchy of this is,

QNetworkRequest request(QUrl(“http://example.com/exampleapi”));

request.setHeader(QNetworkRequest::ContentTypeHeader, “application/xyz”);

QNetworkAccessManager nam;

QNetworkReply *reply = nam.post(request, QByteArray &data);

while(!reply->isFinished())
{
qApp->processEvents();
}
QByteArray response_data = reply->readAll();

reply->deleteLater();

Prince_0912

For set header you can,

void QNetworkRequest::setRawHeader(const QByteArray & headerName, const QByteArray & headerValue);

Sets the value of the known header header to be value, overriding any previously set headers.

void QNetworkRequest::setRawHeader(const QByteArray & headerName, const QByteArray & headerValue)

Sets the header headerName to be of value headerValue. If headerName corresponds to a known header (see QNetworkRequest::KnownHeaders), the raw format will be parsed and the corresponding "cooked" header will be set as well.

for example:
request.setRawHeader(QByteArray("Last-Modified"), QByteArray("Sun, 06 Nov 1994 08:49:37 GMT"));

Pranit Patil

I am trying following code but not getting error like-
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error

void MainWindow::on_pushButton_clicked()
{
QNetworkAccessManager * mgr = new QNetworkAccessManager(this); connect(mgr,SIGNAL(finished(QNetworkReply*)),this,SLOT(onfinish(QNetworkReply*)));
connect(mgr,SIGNAL(finished(QNetworkReply*)),mgr,SLOT(deleteLater()));

QByteArray postData =(" user_token":{"Ej14qoqnm9PxZJWXXHPIzX8L2owzQuIPHA0QewilGs8fzScwp6XoPnsQ4KUb71iv","qr_code":"}");
QUrl serviceURL("https://dev.datoms.io/api/trade/initialization/create_device"); QNetworkRequest request(serviceURL);
request.setRawHeader("Post", "/api/trade/initialization/create_device HTTP/1.1"); request.setRawHeader("Host:", "dev.datoms.io");
request.setRawHeader("Cache-Control:","no-cache ");
mgr->post(request, postData);
}
void MainWindow::onfinish(QNetworkReply *rep)
{
QByteArray bts = rep->readAll();
ui->textBrowser->insertPlainText(bts);
}

Pranit Patil

@Prince_0912 thanks for quick response .
i will try to implement

Pranit Patil

@Prince_0912
simply i implement
in .cpp file
void MainWindow::on_pushButton_clicked()
{
QNetworkRequest request(QUrl("https://dev.datoms.io/api/trade/initialization/create_device"));

//request.setHeader(QNetworkRequest::ContentTypeHeader, "application/xyz");

QNetworkAccessManager manager;
QByteArray data =("user_token\":{\"Ej14qoqnm9PxZJWXXHPIzX8L2owzQuIPHA0QewilGs8fzScwp6XoPnsQ4KUb71iv\",\"qr_code\":\"QGt0Z9Q5J\",\"circuit_version\":\"1.0.0\",\"device_type\":1\"}");

QNetworkReply *reply = manager.post(request, data);

while(!reply->isFinished())
{
qApp->processEvents();
}
QByteArray response_data = reply->readAll();

reply->deleteLater();

}

application Builded but not geeting any response from server
i got this errors
qt.network.ssl: QSslSocket: cannot call unresolved function SSLv23_client_method
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_CTX_new
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error

Prince_0912

Hi @Pranit-Patil ,

These error you can solve by this link .

OR

You can refer this link for implementing in another.

Pranit Patil

i m getting this type of issues-
qt.network.ssl: QSslSocket: cannot call unresolved function SSLv23_client_method
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_CTX_new
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
"Unable to init SSL Context:

i already installed OpenSSL 1.0.2e (32bit) but again same problem faced
anyone knows help me

Thank You.

Pranit Patil

At last, I found the solution. click on following link and download latest version of Win32 OpenSSL v1.1.0h note:Dont download light version ,download 30 MB file

http://slproweb.com/products/Win32OpenSSL.html

after installing OpenSSL opy the following three dll's in the the directory containing your binary file/Debug folder where your .exe file present.

libeay32.dll
libssl32.dll
ssleay32.dll

I solved my problem this one

Prince_0912

Ok finally you got solution. Now make this Topic to Mark as Solved.
Go to right hand side of page -> click on Topic Tools -> Mark as Solved.
Thank you.

Pranit Patil

@Prince_0912 Thank you for your guidlines