I have got a GUI client, that can receive data from a multithreaded server. I then want to be able to send data back to the server. From what I understand with Json, I can use it to send the SQLite statement and also a string. I'm not sure if what I'm trying to implement is the best way forward, but this is what I have got. On the client:

private void addDriverToTable() {
    if (printWriter != null && bufferedReader != null) {

        String driverRef = driverRefTextField.getText();
        String driverNumber = numberTextField.getText();
        String driverCode = codeTextField.getText();
        String driverForename = forenameTextField.getText();
        String driverSurname = surnameTextField.getText();
        String driverDOB = dobTextField.getText();
        String driverNationality = nationalityTextField.getText();
        String driverURL = urlTextField.getText();

        System.out.println("get, " + driverRef + "," + driverNumber + "," + driverCode + "," + driverForename + ","
                + driverSurname + "," + driverDOB + "," + driverNationality + "," + driverURL);

        String insertDriver = "INSERT INTO drivers (driverRef, number, code, forename, surname, dob, nationality, url)" +
                "VALUES (?,?,?,?,?,?,?,?)";

        String addDriver = (driverRef + "," + driverNumber + "," + driverCode + "," + driverForename + "," +
                driverSurname + "," + driverDOB + "," + driverNationality + "," + driverURL);

        addDriverHashMap = new HashMap();
        addDriverHashMap.put(insertDriver, addDriver);

        Gson gson = new Gson();
        JsonObject addDriverData;
        addDriverData = gson.toJsonTree(addDriverHashMap).getAsJsonObject();

        System.out.println(addDriverData);

        String toSend = "add";
        printWriter.println(toSend);
        String toSendJson = String.valueOf(addDriverData);
        printWriter.println(toSendJson);

        String reply = null;

        printWriter.println(addDriverData);
        statusLabel.setText("Status: Adding Driver to database");
        try {
            reply = bufferedReader.readLine();
            statusLabel.setText("Status: Received reply from server");
        }catch (IOException ex){
            statusLabel.setText("IOException " + ex);
        }
        statusLabel.setText("Adding Driver to database");
    }else {
        statusLabel.setText("You must connect to the server first");
    }
}

On the client handler:

@Override
public void run() {
    try{

        threadSays("Waiting for data from client...");
        String lineRead;
        while ((lineRead = bufferedReader.readLine()) != null){
            threadSays("Read data from client: \"" + lineRead + "\".");

            if(command.matches("add")){
                if(command.matches("INSERT")) {
                    JsonObject jsonReply = JsonParser.parseString(arrayRead[0]).getAsJsonObject();
                    addMyDrivers = new ArrayList<>(Arrays.asList(jsonReply));
                    insertDriver = (String) addMyDrivers.get(1);
                    addDriver = (String) addMyDrivers.get(2);
                    replyMessage = "Adding Driver to Database";
                    ThreadedServer.addDriver(insertDriver, addDriver);
                }
            }

            printWriter.println(replyMessage);

        }
    }catch (IOException ex){
        Logger.getLogger(ClientHandlerThread.class.getName()).log(Level.SEVERE, null, ex);
    }finally {
        try {
            threadSays("We have lost connection to client " + connectionNumber + ".");
            ThreadedServer.removeThread(this);
            socket.close();
        }catch (IOException ex){
            Logger.getLogger(ClientHandlerThread.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

Finally on the server:

public static void addDriver(String insertDriver, String addDriver) {
    try (Connection connection = ConnectionSQLite.getConnection()) {
        try (PreparedStatement preparedStatement = connection.prepareStatement(insertDriver)) {

            preparedStatement.setString(1, addDriver);
            preparedStatement.setString(2, addDriver);
            preparedStatement.setString(3, addDriver);
            preparedStatement.setString(4, addDriver);
            preparedStatement.setString(5, addDriver);
            preparedStatement.setString(6, addDriver);
            preparedStatement.setString(7, addDriver);
            preparedStatement.setString(8, addDriver);
            preparedStatement.execute();
        }
    } catch (SQLException ex) {
        Logger.getLogger(SQLException.class.getName()).log(Level.SEVERE, null, ex);
    }

}

The SQLite message appears on the server, I can't work out how to actually get it to then do the insert, the data I'm trying to insert. Any help would be greatly appreciated.