how can i change textbox data remotely in qt?

i have a client and server and a qml file that design the UI of my program.
in qml file there is only a textbox that i want to change the data of textbox to new data that received by client.
i added the files in below.
// main.cpp

Code:

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include "test.h"
#include "test2.h"
#include "server.h"
#include <QDeclarativeComponent>
#include <qquickview.h>
 
int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    Server server;
 
 
qDebug() << "server is listening";
 
 
    return app.exec();
 
}

Code:

// server.cc
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include "server.h"
#include <QDebug>
#include <iostream>
#include <QQmlContext>
#include "test.h"
#include "test2.h"
#include <QDeclarativeComponent>
#include <qquickview.h>
 
Server::Server(QObject* parent): QObject(parent)
{
  connect(&server, SIGNAL(newConnection()),
    this, SLOT(acceptConnection()));
 
 
  server.listen(QHostAddress::Any, 8888);
  qDebug() <<  "vasl shod";
}
 
Server::~Server()
{
  server.close();
}
 
void Server::acceptConnection()
{
  client = server.nextPendingConnection();
  client->write("Hello client\r\n");
 
  connect(client, SIGNAL(readyRead()),
    this, SLOT(startRead()));
}
 
void Server::startRead()
{
 
QString data = QString(client->readAll());
 
client->waitForReadyRead(3000);
QString buf=  client->readAll();
qDebug() << buf;
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:///main.qml")));
 
QObject *rootObject = engine.rootObjects().first();
QObject *qmlObject = rootObject->findChild<QObject*>("ttt");
qmlObject ->setProperty("text","new data");
 
}

Code:

//main.qml
import QtQuick 2.0
import QtQuick 2.2
import QtQuick.Window 2.1
import QtQuick.Window 2.2
import QtQuick.Controls 1.2
 
Window{
    width:400
    height:400
    visible:true
 
    Item {
objectname:"ttt"
      id: rootItem
      property string text: "hello world"
      Text {
          x:0
          y:0
          visible: true
        id: message
        text: rootItem.text
      }
    }
 
}

when run and send data by client the window appear and disappear automatically and i don't know how can i correct it.

I really appreciate it.