FTPClient using QTcpSocket and signals and slots

robsonQTnewbie

SOCKETCONNECTION.h
@#ifndef SOCKETCONNECTION_H
#define SOCKETCONNECTION_H

#include <QMainWindow>
#include <QObject>
#include <iostream>
#include <QTcpSocket>
#include <QAbstractSocket>
#include <QString>

class socketconnection : public QObject
{
Q_OBJECT
public:
explicit socketconnection(QString url, QString login, QString password, QString port, QObject *parent = 0);
QString test();
QString komunikat, message, command;
QString url, login, password, port;
QString directoryList; //pointer to the downloaded directory listing
QString currentPath;
signals:

public slots:
void connected();
private:
QTcpSocket *socket;
QTcpSocket socketTransmit;
};

#endif // SOCKETCONNECTION_H
@

robsonQTnewbie

SOCKETCONNECTION.cpp
@#include "socketconnection.h"
#include "mainwindow.h"
#include <stdio.h>
socketconnection::socketconnection(QString url, QString login, QString password, QString port, QObject *parent) :
QObject(parent)
{
this->url = url;
this->login = login;
this->password = password;
this->port = port;
}
QString socketconnection::test(){
komunikat = "Status: ";
socket = new QTcpSocket(this);
connect(socket, SIGNAL(connected()), this, SLOT(connected()));
komunikat += "Łączenie do serwera FTP...\n";
socket->connectToHost((url.toUtf8().constData()), port.toShort());
if(!socket->waitForConnected(3000)){
komunikat += "Message: ";
komunikat += "Przekroczony limit czasu...\n";
}
return komunikat;
}
void socketconnection::connected()
{
QString adresIP, transfer_port;
std::string passive_connection = "";
std::string oktet[6];
int licznik = 0, portA, portB, portC;
komunikat += "Message: ";
while(message.length() == 0) message = socket->readLine();
komunikat += message;
komunikat += "Polecenie: ";
message = "";
command = "USER " + login + "\r\n";
komunikat += "Polecenie: ";
komunikat += command;
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
while(message.length() == 0) message = socket->readLine();
komunikat += "Message: ";
komunikat += message;
message = "";
command = "PASS " + password + "\r\n";
komunikat += "Polecenie: PASS <nie pokażę Ci hasła>\n";
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
while(message.length() == 0) message = socket->readLine();
komunikat += "Message: ";
komunikat += message;
message = "";
command = "OPTS UTF8 ON\r\n";
komunikat += "Polecenie: ";
komunikat += command;
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
while(message.length() == 0) message = socket->readLine();
komunikat += "Message: ";
komunikat += message;
message = "";
komunikat += "Status: Connected succesfully. Now I'm checking the directory list...\n";
command = "TYPE I\r\n";
komunikat += "Polecenie: ";
komunikat += command;
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
while(message.length() == 0) message = socket->readLine();
komunikat += "Message: ";
komunikat += message;
message = "";
command = "PWD \r\n";
komunikat += "Polecenie: ";
komunikat += command;
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
int i = 0;
while(message.length() == 0){
message = socket->readLine();
}
currentPath = message;
komunikat += "Message: ";
komunikat += message;
message = "";
command = "PASV \r\n";
komunikat += "Polecenie: ";
komunikat += command;
socket->write(command.toUtf8().constData());
socket->waitForBytesWritten(5000);
while(message.length() == 0) message = socket->readLine();
komunikat += "Message: ";
komunikat += message;
passive_connection = message.toUtf8().constData();
message = "";
for(int i = 3; i < passive_connection.length()-2; i++){
if(passive_connection[i] >= '0' && passive_connection[i] <= '9'){
oktet[licznik] += passive_connection[i];
if(passive_connection[i+1] == ',')
{
licznik++;
continue;
}
}
}
adresIP = QString::fromStdString(oktet[0]) + "." + QString::fromStdString(oktet[1]) + "." + QString::fromStdString(oktet[2])
+ "." + QString::fromStdString(oktet[3]);
portA = QString::fromStdString(oktet[4]).toInt();
portB = QString::fromStdString(oktet[5]).toInt();
portC = (portA * 256 + portB);
transfer_port.setNum(portC);
komunikat += "Tworzę połączenie na następujący adres i port: \n";
komunikat += "Adres: " + adresIP + "\n";
komunikat += "Port: " + transfer_port + "\n";

    socketTransmit.connectToHost(adresIP, portC);
    socketTransmit.waitForConnected(2000);
    komunikat += "Polecenie: ";
    command = "LIST \r\n";
    komunikat += command;
    socket->write(command.toUtf8().constData());
    socket->waitForBytesWritten(5000);              
    socketTransmit.waitForBytesWritten(5000);
    socketTransmit.waitForReadyRead(5000);
    socket->waitForBytesWritten(5000);

    socket->waitForBytesWritten(5000);
    message = socket->readLine();  //czekamy na odpowiedź kolejną z socketu poleceń
    komunikat += "Message: ";
    komunikat += message;
    message = "";

    message = socketTransmit.readAll();
    directoryList = message;    //  pobieramy do zmiennej directoryList listing plików i folderów
    if (directoryList != ""){
        komunikat += "Listing plików i folderów przesłąny z powodzeniem!!!:\n";
    }
    else
        komunikat += "Błąd! Nie udało mi się pobrać listy plików i folderów!!!\n";
    //komunikat += message;
    message = "";
    i = 0;
    while(message.length() == 0){
        i++;
        message = socket->readLine();
        if(i == 32768)
        {
            message = "Błąd podczas transmisji polecenia";
            break;
        }
    }
    komunikat += "Message: ";
    komunikat += message;
    message = "";
}

@

robsonQTnewbie

I know my code isn't nice but I've just started my QT experience, so I hope that you'll understand and can help me. Thanks a lot :)

SGaist

There are indeed several things that I don't follow:

Why are you mixing std::string and QString ? Currently it just complicates your code without any benefits
Why are you using pointers to QString ?

You are also creating memory leaks with your custom dialogs.

Anyway, for your original problem. You are doing everything in the connected slot, which is a bad idea. You need to refactor that and split the logic for the various commands you want to send in their own functions

robsonQTnewbie

I'm mixing QString with std::string because I couldn't filter the QString like a simple array, so I decided to go on the easiest way and parse it to std::string.

I need pointers to QString because I have no idea how get access to one variable from one class in another class. I think pointers are a good method to get the content from variables....

Which custom dialogs do you mean? I thinked about your advice to split to signal and slot system but I have trouble with it..... now i have something like that:
@#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_pushButton_clicked() // connect Button
{
commandSocket = new QTcpSocket(this);

login = ui->loginValue->text();
url = ui->urlValue->text();
password = ui->passwordValue->text();
port = ui->portValue->text();
qint64 timeout = 4000;

connect(commandSocket, SIGNAL(connected()), this, SLOT(connected()));
connect(commandSocket, SIGNAL(bytesWritten(timeout)), this, SLOT(getMessage()));
qDebug() << "Connecting...";

commandSocket->connectToHost(url, port.toShort());
if(!commandSocket->waitForConnected(3000)){
    qDebug() << "Przekroczony limit czasu...\n";
}

}

void MainWindow::connected()
{
qDebug() << "In connected()...";
sendMessage("USER ", login);

}
void MainWindow::sendMessage(QString message, QString argument)
{
qDebug() << "in sendMessage...";
QString displayedArgument, command;
if(message == "PASS ")
displayedArgument = "SECRET_PASSWORD...";
else
displayedArgument = argument;
command = message + argument + "\r\n";
commandSocket->write(command.toUtf8().constData());
commandSocket->waitForBytesWritten(10000);

ui->textBrowser->setOverwriteMode(false);
ui->textBrowser->setText("Polecenie: " + message + displayedArgument + "\n");
qDebug() << "send message done...";

}
void MainWindow::getMessage()
{
qDebug() << "In getMessage()...";
QString message = "";
//while(message == "")
message = commandSocket->readLine();

qDebug() << message;
ui->textBrowser->setOverwriteMode(false);
ui->textBrowser->setText(message);

}@
and unfortunately it's not working:/
PS. I decidet to put everything in the mainwindow.cpp.

SGaist

What do you mean by "can't filter like a simple array" ?

You should have a look at the fortune client/server example for inspiration

robsonQTnewbie

I mean something like that:
@
QString someQString = "I like Qt!", outputQString = "";
for(int i = 0; i < someQString.length(); i++)
{
if(someQString[i] != " ")
outputString += someQString[i];
}
@

SGaist

You want to remove all white spaces in the string ?
From the top of my head:
@
someQString.replace(QRegular[removed]"\s"), "");
@

Replace QRegularExpression by QRegExp if you are on Qt 4

robsonQTnewbie

Thanks:) I moved forward with my project and now i need help with downloading files. The problem is that, when I download a file (first .txt) the data go on the socket but not everything. When i download a small file it works fine, but when I download a bigger file it looses data. :/ Do you have a advice form me?

P.S. I start the download from the transfer socket, when on the commandLineSocket is the command RETR succesfully transmited.

SGaist

Look at readyRead and the asynchronousness handling of IO devices

Call for Presentations - Qt World Summit

FTPClient using QTcpSocket and signals and slots