Bdtjtk

I'm writing an application with JavaFX, Scene Builder and SQlite

I have combobox with values(id) that goes from SQLite database.I have 2 textArias. I have a button "Add" that has a method void addCard(ActionEvent event). The method add text from textArias and apply it to particular columns in SQLite.

The problem is: when I try to add values to SQLite and click a button and then I open combobox, I don't see added ID, but when I close the window and open it again combobox display my added id.

It is very annoying to close and open window every time when I want to see the added result in combobox

• Model class holds all logic


• Controller Class operate between Model and view


• Persistent Queries class holds all queries to/from SQLite

How to display new added ID after clicking on the button "Add"?

This video shows how my application work:

Video

Model class:

package src.card;



import javafx.collections.FXCollections;

import javafx.collections.ObservableList;



import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;



public class Cards {



  PersistentQueries pq = new PersistentQueries();



  final ObservableList OPTIONS = FXCollections.observableArrayList();



  Connection connection;

  PreparedStatement pst = null;

  ResultSet rs = null;









  public Cards() {

try {

  this.connection = DbConnection.getConnection();

} catch (SQLException ex) {

  ex.printStackTrace();

}



if (this.connection == null) {

  System.out.println("connection is not successful!");

  System.exit(1);

}



  }





   public ObservableList getOPTIONS() {return OPTIONS;}







   //add ID of cards to combobox

  void fillCombobox() {

   try {

  pst = connection.prepareStatement(pq.getSqlSelectID());

  rs = pst.executeQuery();



  while (rs.next()) {

    OPTIONS.add(rs.getString("ID"));

  }



  pst.close();

  rs.close();



} catch (SQLException e) {

  e.printStackTrace();

   }

  }



  //check if database is connected

  public boolean isDbConnected() {

    return this.connection != null;

  }

}

Controller Class:

 package src.card;



import javafx.event.ActionEvent;

import javafx.fxml.FXML;

import javafx.fxml.Initializable;

import javafx.scene.control.ComboBox;

import javafx.scene.control.Label;

import javafx.scene.control.TextArea;

import src.card.Cards;

import src.card.Context;

import src.card.DbConnection;

import src.card.PersistentQueries;



import java.net.URL;

import java.sql.*;

import java.util.ResourceBundle;









public class QuestController implements Initializable {



  @FXML  private TextArea ta_questText, ta_answerText;

  @FXML  private Label questId, error;

  @FXML  private ComboBox<String> combobox_question;



  Cards cards = new Cards();

  PersistentQueries pq = new PersistentQueries();



  @Override

  public void initialize(URL location, ResourceBundle resources) {



//register QuestController in  Context Class

Context.getInstance().setQuestController(this);



cards.fillCombobox();

combobox_question.setItems(cards.getOPTIONS());



  }



//adding cards to database

 @FXML

  void addCard(ActionEvent event) {



    if (ta_questText.getText().equals("") || 

   ta_answerText.getText().equals("")) {

  error.setText("All fields are required!");

} else {

  try {

    error.setText("");

    Connection conn = DbConnection.getConnection();

    PreparedStatement stmt = conn.prepareStatement(pq.getSqlInsert());

    stmt.setString(1, this.ta_questText.getText());

    stmt.setString(2, this.ta_answerText.getText());

    ta_questText.setText("");

    ta_answerText.setText("");

    stmt.execute();

    conn.close();





  } catch (SQLException e) {

    e.printStackTrace();

     }

    }



  }



  @FXML

  void idList(ActionEvent event) {



  questId.setText(combobox_question.getValue() + ".");



   }

}

PersistentQueries Class

package src.card;



public class PersistentQueries {



  private String sqlInsert = "INSERT INTO Cards(question, answer) VALUES 

 (?,?)";

  private String sqlSelectID = "SELECT ID FROM Cards";

  private String sqlSelect = "SELECT question and answer FROM Cards";





  public String getSqlInsert() {

   return sqlInsert;

  }



  public void setSqlInsert(String sqlInsert) {

    this.sqlInsert = sqlInsert;

  }





  public String getSqlSelectID() {

   return sqlSelectID;

   }



  public void setSqlSelectID(String sqlSelectID) {

   this.sqlSelectID = sqlSelectID;

  }



   public String getSqlSelect() {

   return sqlSelect;

  }



  public void setSqlSelect(String sqlSelect) {

   this.sqlSelect = sqlSelect;

  }

}

PROBLEM SOLVED!

in QuestController in the method @FXML void addCard(ActionEvent event) I added

cards.getOBS().clear();

It removes all objects from Observable list

then, I called method from Cards Class that reads all new data from SQLite and add it to Observable list

cards.fillCombobox();

and then I just close all connections:

    pst.close();

    rs.close();

    conn.close();

My rewritten method looks like this:

 /adding cards to database, update combobox and clear label text

  @FXML  void addCard(ActionEvent event) {



if (ta_questText.getText().equals("") || ta_answerText.getText().equals("")) {

  error.setText("All fields are required!");

} else {

  try {



    error.setText("");

    Connection conn = DbConnection.getConnection();

    pst = conn.prepareStatement(pq.getSqlInsert());

    pst.setString(1, this.ta_questText.getText());

    pst.setString(2, this.ta_answerText.getText());

    pst.execute();



    pst = conn.prepareStatement(pq.getSqlSelectID());

    rs = pst.executeQuery();



    ta_questText.clear();

    ta_answerText.clear();

    cards.getOBS().clear();

    questId.setText("");



   cards.fillCombobox();



    pst.close();

    rs.close();

    conn.close();





  } catch (SQLException e) {

    e.printStackTrace();

  }

}



 }