I can upload files to ftp. But how do I delete files
Qt Version: 5.2.0
How to do deleteFile function.
I can upload files to ftp. But how do I delete file
just delete any file on the ftp I would like to, please help. Qnetworkaccessmanag will be using.
no Qftp.
class Uploader: public QObject
{
Q_OBJECT
public:
Uploader(QObject *p = 0): QObject(p) { }
void fileupload(const QString &file) //OK NO PROBLEM
{
QFileInfo finfo(file);
QUrl url("ftp://www.website.com/"+finfo.fileName());
url.setUserName("username");
url.setPassword("pass");
data = new QFile(file, this);
if (data->open(QIODevice::ReadOnly)) {
reply = nam.put(QNetworkRequest(url), data);
connect(reply, SIGNAL(uploadProgress(qint64, qint64)), SLOT(uploadProgress(qint64, qint64)));
connect(reply, SIGNAL(finished()), SLOT(uploadDone()));
}
else
qDebug() << "Oops";
}
void deletefile(QUrl ftpUrl) ????????????
{
HOW CODE ????????
}
public slots:
void uploadProgress(qint64 bytesSent, qint64 bytesTotal) {
qDebug() << "Uploaded" << bytesSent << "of" << bytesTotal;
}
void uploadDone() {
qDebug() << "Finished" << reply->error();
data->deleteLater();
reply->deleteLater();
}
private:
QNetworkAccessManager nam;
QFile *data;
QNetworkReply *reply;
};
Related
I want to create two-way communicate beetwen my Qt Apps. I want to use QProcess to do this. I'm calling sucesfully child app from root app and sending test data without any erro, but I can't recive any data in child app. I'll be gratefull for any help. I'm using Qt 4.7.1. Below my test code:
Root app:
InterProcess::InterProcess(QObject *parent) : QProcess(parent)
{
process = new QProcess(this);
process->start(myChildApp);
process->waitForStarted();
process->setCurrentWriteChannel(QProcess::StandardOutput);
process->write("Test");
connect( process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(error(QProcess::ProcessError)) );
connect( process, SIGNAL(readyReadStandardError()), this, SLOT(readyReadStandardError()) );
connect( process, SIGNAL(readyReadStandardOutput()), this, SLOT(readyReadStandardOutput()) );
QByteArray InterProcess::read()
{
QByteArray readBuffer = process->readAllStandardOutput();
return readBuffer;
}
void InterProcess::error( QProcess::ProcessError error )
{
qDebug() << "Error!";
qDebug() << error;
}
void InterProcess::readyReadStandardError()
{
qDebug() << "Ready to read error.";
qDebug() << process->readAllStandardError();
}
void InterProcess::readyReadStandardOutput()
{
qDebug() << "The output:";
QByteArray readBuffer = process->readAllStandardOutput();
qDebug() << readBuffer;
}
Child app:
InterProcess::InterProcess(QObject *parent) : QProcess(parent)
{
process = new QProcess();
process->setCurrentReadChannel(QProcess::StandardOutput);
connect( process, SIGNAL(readyRead()), this, SLOT(readyReadStandardOutput()));
connect( process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(error(QProcess::ProcessError)) );
connect( process, SIGNAL(readyReadStandardError()), this, SLOT(readyReadStandardError()) );
connect( process, SIGNAL(readyReadStandardOutput()), this, SLOT(readyReadStandardOutput()) );
process->waitForReadyRead(5000);
}
void InterProcess::readyReadStandardError()
{
qDebug() << "Ready to read error.";
qDebug() << process->readAllStandardError();
setText("REady error");
}
void InterProcess::readyReadStandardOutput()
{
setMessage("2");
qDebug() << "The output:";
QByteArray readBuffer = process->readAllStandardOutput();
qDebug() << readBuffer;
}
void InterProcess::error( QProcess::ProcessError error )
{
qDebug() << "Error!";
qDebug() << error;
setText(QString(error));
}
It's very hard to explain in one answer all mistakes, so just look at code and ask if you still got problems.
Here is example of using QProcess as IPC.
This is your main process, that creates additional process and connects to its signals
MyApplicaiton.h
#ifndef MYAPPLICATION_H
#define MYAPPLICATION_H
#include <QApplication>
class InterProcess;
class MyApplication : public QApplication {
Q_OBJECT
public:
MyApplication(int &argc, char **argv);
signals:
void mainApplicationSignal();
private slots:
void onInterProcessSignal();
private:
InterProcess *mProcess;
};
#endif // MYAPPLICATION_H
MyApplicaiton.cpp
#include "MyApplication.h"
#include "InterProcess.h"
MyApplication::MyApplication(int &argc, char **argv) : QApplication(argc, argv) {
mProcess = new InterProcess(this);
connect(mProcess, SIGNAL(interProcessSignal()),
this, SLOT(onInterProcessSignal()));
mProcess->start();
}
void MyApplication::onInterProcessSignal() {}
This is example implementation of your interProcess class:
InterProcess.h
class InterProcess : public QProcess {
Q_OBJECT
public:
explicit InterProcess(QObject *parent = nullptr);
signals:
void interProcessSignal();
private slots:
void onMainApplicationSignal();
};
InterProcess.cpp
#include "InterProcess.h"
#include "MyApplication.h"
InterProcess::InterProcess(QObject *parent) : QProcess(parent) {
if(parent) {
auto myApp = qobject_cast<MyApplication *>(parent);
if(myApp) {
connect(myApp, SIGNAL(mainApplicationSignal()),
this, SLOT(onMainApplicationSignal()));
}
}
}
void InterProcess::onMainApplicationSignal() {}
Locally, using UDP is very convenient and efficient
void Server::initSocket() {
udpSocket = new QUdpSocket(this);
udpSocket->bind(QHostAddress::LocalHost, 7755);
connect(udpSocket, SIGNAL(readyRead()), this, SLOT(readPendingDatagrams()));}
void Server::readPendingDatagrams(){
while (udpSocket->hasPendingDatagrams()) {
QByteArray datagram;
datagram.resize(udpSocket->pendingDatagramSize());
QHostAddress sender;
quint16 senderPort;
udpSocket->readDatagram(datagram.data(), datagram.size(),
&sender, &senderPort);
processTheDatagram(datagram);
}}
When I try to downloading file up to 50mb example, no problem, but with a big files give the following error
void MainWindow::downloadFile() {
QNetworkRequest requests;
requests.setUrl(QUrl("https://urlToFile"));
QSslConfiguration configSsl = QSslConfiguration::defaultConfiguration();
configSsl.setProtocol(QSsl::AnyProtocol);
requests.setSslConfiguration(configSsl);
QNetworkAccessManager *manager5 = new QNetworkAccessManager(this);
QNetworkReply *reply5;
reply5 = manager5->get( requests );
connect(manager5, SIGNAL(finished(QNetworkReply*)), this, SLOT(downloadFinished(QNetworkReply*)));
}
void MainWindow::downloadFinished(QNetworkReply *data) {
QFile localFile("fileName");
if (!localFile.open(QIODevice::WriteOnly))
return;
localFile.write(data->readAll());
localFile.close();
}
In your code, You are holding the whole file in memory until the download process finishes (that is when QNetworkAccessManager::finished() signal gets emitted). Of course, this is not the best way to deal with large files.
Remember that QNetworkReply is a QIODevice. This means that you should use the readyRead() signal to save data chunks to the disk as soon as they are received from the network, in order to avoid holding the whole file in memory until the download is finished.
Here is a minimal complete example:
#include <QtNetwork>
int main(int argc, char* argv[]){
QCoreApplication a(argc, argv);
QNetworkAccessManager nam;
QFile file("downloadedFile.xxx");
if(!file.open(QIODevice::ReadWrite)) return 1;
QNetworkRequest request(QUrl("http://download_url/..."));
QNetworkReply* reply = nam.get(request);
QObject::connect(reply, &QNetworkReply::readyRead, [&]{
//this will be called every time a chunk of data is received
QByteArray data= reply->readAll();
qDebug() << "received data of size: " << data.size();
file.write(data);
});
//use the finished signal from the reply object to close the file
//and delete the reply object
QObject::connect(reply, &QNetworkReply::finished, [&]{
qDebug() << "finished downloading";
QByteArray data= reply->readAll();
file.write(data);
file.close();
reply->deleteLater();
a.quit();
});
return a.exec();
}
Update:
I have wrapped the whole thing in a class FileDownloader, which can be used to download a file using QNetworkAccessManager, Here is an example of using this class:
#include <QtWidgets>
#include <QtNetwork>
//downloads one file at a time, using a supplied QNetworkAccessManager object
class FileDownloader : public QObject{
Q_OBJECT
public:
explicit FileDownloader(QNetworkAccessManager* nam, QObject* parent= nullptr)
:QObject(parent),nam(nam)
{
}
~FileDownloader(){
//destructor cancels the ongoing dowload (if any)
if(networkReply){
a_abortDownload();
}
}
//call this function to start downloading a file from url to fileName
void startDownload(QUrl url, QString fileName){
if(networkReply) return;
destinationFile.setFileName(fileName);
if(!destinationFile.open(QIODevice::WriteOnly)) return;
emit goingBusy();
QNetworkRequest request(url);
networkReply= nam->get(request);
connect(networkReply, &QIODevice::readyRead, this, &FileDownloader::readData);
connect(networkReply, &QNetworkReply::downloadProgress,
this, &FileDownloader::downloadProgress);
connect(networkReply, &QNetworkReply::finished,
this, &FileDownloader::finishDownload);
}
//call this function to abort the ongoing download (if any)
void abortDownload(){
if(!networkReply) return;
a_abortDownload();
emit backReady();
}
//connect to the following signals to get information about the ongoing download
Q_SIGNAL void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
Q_SIGNAL void downloadSuccessful();
Q_SIGNAL void downloadError(QString errorString);
//the next two signals are used to indicate transitions between busy and
//ready states of the file downloader, they can be used to update the GUI
Q_SIGNAL void goingBusy();
Q_SIGNAL void backReady();
private:
Q_SLOT void readData(){
QByteArray data= networkReply->readAll();
destinationFile.write(data);
}
Q_SLOT void finishDownload(){
if(networkReply->error() != QNetworkReply::NoError){
//failed download
a_abortDownload();
emit downloadError(networkReply->errorString());
} else {
//successful download
QByteArray data= networkReply->readAll();
destinationFile.write(data);
destinationFile.close();
networkReply->deleteLater();
emit downloadSuccessful();
}
emit backReady();
}
//private function, cleans things up when the download is aborted
//(due to an error or user interaction)
void a_abortDownload(){
networkReply->abort();
networkReply->deleteLater();
destinationFile.close();
destinationFile.remove();
}
QNetworkAccessManager* nam;
QUrl downloadUrl;
QFile destinationFile;
QPointer<QNetworkReply> networkReply;
};
//A sample GUI application that uses the above class
class Widget : public QWidget{
Q_OBJECT
public:
explicit Widget(QWidget* parent= nullptr):QWidget(parent){
layout.addWidget(&lineEditUrl, 0, 0);
layout.addWidget(&buttonDownload, 0, 1);
layout.addWidget(&progressBar, 1, 0);
layout.addWidget(&buttonAbort, 1, 1);
layout.addWidget(&labelStatus, 2, 0, 1, 2);
lineEditUrl.setPlaceholderText("URL to download");
connect(&fileDownloader, &FileDownloader::downloadSuccessful,
this, &Widget::downloadFinished);
connect(&fileDownloader, &FileDownloader::downloadError,
this, &Widget::error);
connect(&fileDownloader, &FileDownloader::downloadProgress,
this, &Widget::updateProgress);
connect(&buttonDownload, &QPushButton::clicked,
this, &Widget::startDownload);
connect(&buttonAbort, &QPushButton::clicked,
this, &Widget::abortDownload);
showReady();
//use goingBusy() and backReady() from FileDownloader signals to update the GUI
connect(&fileDownloader, &FileDownloader::goingBusy, this, &Widget::showBusy);
connect(&fileDownloader, &FileDownloader::backReady, this, &Widget::showReady);
}
~Widget() = default;
Q_SLOT void startDownload(){
if(lineEditUrl.text().isEmpty()){
QMessageBox::critical(this, "Error", "Enter file Url", QMessageBox::Ok);
return;
}
QString fileName =
QFileDialog::getSaveFileName(this, "Destination File");
if(fileName.isEmpty()) return;
QUrl url= lineEditUrl.text();
fileDownloader.startDownload(url, fileName);
}
Q_SLOT void abortDownload(){
fileDownloader.abortDownload();
}
Q_SLOT void downloadFinished(){
labelStatus.setText("Download finished successfully");
}
Q_SLOT void error(QString errorString){
labelStatus.setText(errorString);
}
Q_SLOT void updateProgress(qint64 bytesReceived, qint64 bytesTotal){
progressBar.setRange(0, bytesTotal);
progressBar.setValue(bytesReceived);
}
private:
Q_SLOT void showBusy(){
buttonDownload.setEnabled(false);
lineEditUrl.setEnabled(false);
buttonAbort.setEnabled(true);
labelStatus.setText("Downloading. . .");
}
Q_SLOT void showReady(){
buttonDownload.setEnabled(true);
lineEditUrl.setEnabled(true);
buttonAbort.setEnabled(false);
progressBar.setRange(0,1);
progressBar.setValue(0);
}
QGridLayout layout{this};
QLineEdit lineEditUrl;
QPushButton buttonDownload{"Start Download"};
QProgressBar progressBar;
QPushButton buttonAbort{"Abort Download"};
QLabel labelStatus{"Idle"};
QNetworkAccessManager nam;
FileDownloader fileDownloader{&nam};
};
int main(int argc, char* argv[]){
QApplication a(argc, argv);
Widget w;
w.show();
return a.exec();
}
#include "main.moc"
I'm trying to make client and server using QTcpSocket and QTcpServer.
So, what happens to server.
I run the server, it starts listening (successfully [checked by myself])
I run client, enter 127.0.0.1 for IP address and 30000 for port
Client says that connection estabilished
Server doesn't do anything, just keep waiting
Parts of my program:
//server-work.h
#ifndef SERVERWORK_H
#define SERVERWORK_H
#include <QtCore>
#include <QSqlError>
#include <QDebug>
#include <QSqlQuery>
#include <unistd.h>
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QTcpSocket>
#include <QtSql/QSqlDatabase>
#include "lssclient.h"
class LSSClient;
class LTcpServer : public QTcpServer
{
Q_OBJECT
public:
class LTWorkWithClients : public QThread
{
//Q_OBJECT
public:
LTcpServer* server;
LTWorkWithClients(QObject* parent = 0, LTcpServer *server = 0):
QThread(parent)
{
this->server = server;
}
protected:
void run() {
qDebug() << "started";
server->workWithIncomingConnection();
}
};
QSqlDatabase db; // clients in database
LTWorkWithClients* t_workWithClients;
QQueue<quintptr> clientsToBeAttached;
QList<LSSClient*> clients;
LResult workWithIncomingConnection ();
LResult serverInit ();
LResult createDatabase ();
static QTextStream& qStdout ();
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
protected:
private:
};
#endif // SERVERWORK_H
I know that this nested thread class is strongly wrong way to do this thing, but i don't have much time to do it correctly
// server-work.cpp [PART]
LResult LTcpServer::serverInit()
{
checkError;
db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName("serverDB");
if (!db.open()) {
qDebug() << "Error opening database...";
qDebug() << db.lastError().text();
return LVError;
} else {
qDebug() << "Database successfully opened";
}
if(!this->listen(QHostAddress::Any, 30000)){
qDebug() << "Error starting listening...";
return LVError;
} else {
qDebug() << "Start listening successfully";
}
t_workWithClients = new LTWorkWithClients(this, this);
t_workWithClients->start();
return LVSuccess;
}
void LTcpServer::incomingConnection(qintptr socketDescriptor)
{
qDebug() << Q_FUNC_INFO << " new connection";
clientsToBeAttached.enqueue(socketDescriptor);
qDebug() << "here1";
}
LResult LTcpServer::workWithIncomingConnection()
{
bool toExit = false;
while (!toExit) {
checkError;
qDebug() << "1";
if (clientsToBeAttached.length() != 0) {
quintptr eachClientDescriptor = clientsToBeAttached.dequeue();
qDebug() << "2";
LSSClient* client = new LSSClient(this);
client->server = this;
client->socket->setSocketDescriptor(eachClientDescriptor);
qDebug() << "3";
client->registered = false;
client->server = this;
qDebug() << client->socket->localAddress();
connect(client->socket, SIGNAL(readyRead()), client, SLOT(onSokReadyRead()));
connect(client->socket, SIGNAL(connected()), client, SLOT(onSokConnected()));
connect(client->socket, SIGNAL(disconnected()), client, SLOT(onSokDisconnected()));
connect(client->socket, SIGNAL(error(QAbstractSocket::SocketError)),client, SLOT(onSokDisplayError(QAbstractSocket::SocketError)));
clients.append(client);
}
usleep(1000000);
}
return LVSuccess;
}
So, server just keep writing 1 (nothing more) every second, but client says that it is connected to the server.
This structure might help...
in your ltcpserver.h file:
class LTcpServer : public QTcpServer
{
Q_OBJECT
public:
explicit LTcpServer(QObject * parent = 0);
void incomingConnection(qintptr socketDescriptor) Q_DECL_OVERRIDE;
private:
QThread *myThread;
};
and in your ltcpserver.cpp:
LTcpServer::LTcpServer(QObject * parent) : QTcpServer(parent)
{
if(this->listen(QHostAddress::Any,30000))
{
qDebug() << "server started...";
}
else
{
qDebug() << "server could not be started...";
}
myThread = new QThread();
myThread->start();
}
void LTcpServer::incomingConnection(qintptr socketDescriptor)
{
LSSClient * yourClient = new LSSClient(socketDescriptor);
yourClient->moveToThread(myThread);
clients->append(yourClient);
}
and in your lssclient.h
class LSSClient: public QObject
{
Q_OBJECT
public:
explicit LSSClient(qintptr socketDescriptor,QObject * parent = 0);
private:
void setupSocket(qintptr socketDescriptor);
QTcpSocket * socket;
public slots:
void readyRead();
void disconnected();
};
and in your lssclient.cpp
LSSClient::LSSClient(qintptr socketDescriptor,QObject * parent) : QObject(parent)
{
setupSocket(qintptr socketDescriptor);
}
void LSSClient::setupSocket(qintptr socketDescriptor)
{
socket = new QTcpSocket(this);
socket->setSocketDescriptor(sDescriptor);
connect(socket,SIGNAL(readyRead()),this,SLOT(readyRead()));
connect(socket,SIGNAL(disconnected()),this,SLOT(disconnected()));
}
void LSSClient::readyRead()
{
// do whatever you want here with incoming data
}
void LSSClient::disconnected()
{
// do what happens to client when disconnected
}
Reply returns empty body content if reply->error() != QNetworkReply::NoError,
but actually response has a content.
How can I read it?
void MainWindow::on_pushButton_clicked()
{
manager = new QNetworkAccessManager(this);
connect( manager, SIGNAL(finished(QNetworkReply*)),
this, SLOT(replyFinished(QNetworkReply*)));
manager->get(QNetworkRequest(QUrl("http://...")));
}
void MainWindow::replyFinished(QNetworkReply* reply)
{
if (reply->error() == QNetworkReply::NoError)
{
QByteArray content= reply->readAll();
QDebug() << QString body(content); // ok
} else {
QByteArray content= reply->readAll();
QDebug() << QString body(content); //empty, but must be exist
}
}
I'm writing a Qt program to get an image from site and insert in a QLabel. When I send my request my screen freezes and nothing more occurs.
Notice I'm new in Qt.
Based on my initial knowledge of Qt it's enough send a signal when download is finished.
...
MapReader::MapReader(QWidget *parent, Qt::WFlags flags)
: QMainWindow(parent, flags)
{
ui.setupUi(this);
imageLabelMap = ui.imageMap;
getImageButton = ui.getImageButton;
networkManager = new QNetworkAccessManager(this);
setup();
}
MapReader::~MapReader()
{
}
void MapReader::setup()
{
QObject::connect(getImageButton, SIGNAL(clicked()), this, SLOT(triggerDownload()));
QObject::connect(networkManager, SIGNAL(finished(QNetworkReply*)), this, SLOT(finishedDownload(QNetworkReply*)));
}
void MapReader::setImage(QByteArray imageBytes)
{
QImage map;
...
}
void MapReader::triggerDownload()
{
QUrl url("http://images.tsn.ca/images/stories/2012/09/26/terrydunfield_2035-430x298.jpg");
QNetworkReply* reply = networkManager->get(QNetworkRequest(url));
QObject::connect(reply, SIGNAL(readyRead()), &loop, SLOT(quit()));
}
void MapReader::finishedDownload(QNetworkReply* reply)
{
reply->deleteLater();
QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
QVariant redirectionTargetUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
if(reply->error() != QNetworkReply::NoError)
{
QMessageBox msgBox;
msgBox.setWindowTitle("Error");
msgBox.setInformativeText("Error on downloading file: \n"+reply->errorString());
msgBox.exec();
return;
}
QVariant attribute = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
if (attribute.isValid())
{
QUrl url = attribute.toUrl();
qDebug() << "must go to:" << url;
return;
}
setImage(reply->readAll());
}
I think there is some code missing that might give us a clue. You have
QObject::connect(reply, SIGNAL(readyRead()), &loop, SLOT(quit()));
But I don't see where loop is defined? Sounds like you are running an additional event loop?
Regardless, you don't need that. This should be as simple as:
void MapReader::triggerDownload()
{
QUrl url("http://images.tsn.ca/images/stories/2012/09/26/terrydunfield_2035-430x298.jpg");
QNetworkReply* reply = networkManager->get(QNetworkRequest(url));
QObject::connect(reply, SIGNAL(finished()), this, SLOT(finishedDownload()));
}
void MapReader::finishedDownload()
{
QNetworkReply *reply = qobject_cast<QNetworkReply *>(sender()); // sender() allows us to see who triggered this slot - in this case the QNetworkReply
QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
QVariant redirectionTargetUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
if(reply->error() != QNetworkReply::NoError)
{
QMessageBox msgBox;
msgBox.setWindowTitle("Error");
msgBox.setInformativeText("Error on downloading file: \n"+reply->errorString());
msgBox.exec();
return;
}
QVariant attribute = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
if (attribute.isValid())
{
QUrl url = attribute.toUrl();
qDebug() << "must go to:" << url;
return;
}
setImage(reply->readAll());
reply->deleteLater();
}
Make sure you have defined finishedDownload() as a slot in your header file