C++ integration Qt

So I wrote a Qt quick application that takes user inputs and stores them in a json file. I now want to add a feature that lets me recall the data in my file and display it in a text field within my application. I can get the text in the C++ portion of my application, Im just not sure how to display it in my user interface. Here is the code to get the text from my json file.

void Jsonfile:: display(){

    //1. Open the QFile and write it to a byteArray and close the file
    QFile file;
    file.setFileName("data.json");
    if(!file.open(QIODevice::ReadOnly)){
        qDebug() << "file couldn't be opened/found";
        return;
    }

    QByteArray byteArray;
    byteArray = file.readAll();
    file.close();

    //2. Format the content of the byteArray as QJsonDocument
    //and check on parse Errors
    QJsonParseError parseError;
    QJsonDocument jsonDoc;
    jsonDoc = QJsonDocument::fromJson(byteArray, &parseError);
    if(parseError.error != QJsonParseError::NoError){
           qWarning() << "Parse error at " << parseError.offset << ":" << parseError.errorString();
           return;
       }
    QTextStream textStream(stdout);
    textStream << jsonDoc.toJson(QJsonDocument::Indented);


}