[SOLVED] How to download files from SourceForge using Qt

[inopportuno]

I'm writing a C++ application using Qt framework that needs to download a file from SourceForge.

I have to download this file https://sourceforge.net/projects/meshlab/files/updates/1.3.3/updates.xml

I wrote the following code using Qt and the QHttp class:

@QFile tmpfile;
int hostreqid;
int checkreqid;
...
...
tmpfile.setFileName("updates.xml");
hostreqid = http.setHost("sourceforge.net",QHttp::ConnectionModeHttp);
checkreqid = http.get(QString(QUrl::toPercentEncoding("/projects/meshlab/files/updates/1.3.3/updates.xml")),&tmpfile);
...
...
void parseAnswer( int id,bool error )
{
if (!error && (id == checkreqid))
{
...
tmpfile.close();
}
if (error)
{
QHttp::Error err = http.error();
QString errstrg = http.errorString();
}
}@
Both QHttp::setHost and QHttp::get are not blocking functions returning immediately an int id. When the http file transfer completed the parseAnswer function is automatically called. The problem is that inside the updates.xml file I got, instead the data I was expecting I received an html file from SouceForge reporting an "Invalid Project" error.

I noticed that when I access the https://sourceforge.net/projects/meshlab/files/updates/1.3.3/updates.xml from browser I have been redirected to https://sourceforge.net/projects/meshlab/files/updates/1.3.3/updates.xml/download page. I tried also this other address but nothing changed.

Please, notice that I'm using Http protocol (QHttp::ConnectionModeHttp) instead of the https. If I could I would wish to avoid to use the https. Can be the source of the problem?

Thanks a lot!

[AcerExtensa]

You can't download from sourceforge directly, use one of it's mirrors, or generate url to be directly redirected to the right mirror:
@
QUrl url("http://downloads.sourceforge.net/project/meshlab/updates/1.3.3/updates.xml?r=&ts="+QString::number(QDateTime::currentDateTime ().toTime_t())+"&use_mirror=heanet");
@

heanet is the example mirror in this case.

[inopportuno]

Thanks a lot for your suggestion! Unfortunately now I'm getting an empty file...Have you some other idea? Really really thanks for your help

[twsimpson]

Make sure you handle the HTTP redirect and initiate another request with the location reported back.

[AcerExtensa]

This works for me:

header:
@
#ifndef SFORGE_H
#define SFORGE_H

#include <QNetworkAccessManager>
#include <QNetworkReply>

class SForge : public QNetworkAccessManager
{
Q_OBJECT
public:
explicit SForge(QObject *parent = 0);

private slots:
void fin(QNetworkReply *);

};

#endif // SFORGE_H
@

code:
@
#include "sforge.h"
#include <QDateTime>
#include <QUrl>
#include <QNetworkRequest>
#include <QDebug>

SForge::SForge(QObject *parent):QNetworkAccessManager(parent)
{
QUrl url("http://downloads.sourceforge.net/project/meshlab/updates/1.3.3/updates.xml?r=&ts="+QString::number(QDateTime::currentDateTime().toTime_t())+"&use_mirror=heanet");

connect(this, SIGNAL(finished(QNetworkReply*)), this, SLOT(fin(QNetworkReply*)));

QNetworkRequest req(url);
this->get(req);

}

void SForge::fin(QNetworkReply * reply)
{
if(reply->error() != QNetworkReply::NoError)
qDebug() << reply->errorString();

if(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt() == 307 || reply->rawHeaderList().contains("Location"))
{
    QNetworkRequest req(reply->header(QNetworkRequest::LocationHeader).toString());
    this->get(req);
    return;
}

qDebug() << __LINE__ << reply->bytesAvailable() << reply->readAll();

}
@

[inopportuno]

I love you! You own my soul! Probably my problem was (also like Terence suggested) that I didn't manage the redirect... Thanks a lot! Really Really thanks!

[AcerExtensa]

I'm glad I could help you! :) Please add "[SOLVED]" prefix, left to the topic subject. Thanks!