How to dump database from MariaDB to FXML table from Scene Builder JavaFX?

Question

Java

Hello. Started learning Java. I really liked the Scene Builder technology. I'm trying to display a table from a MariaDB database in the GUI, but I'm getting an error that cannot be resolved. I would be very grateful for any help.
Main.java

package sample;
    
    import javafx.application.Application;
    import javafx.fxml.FXMLLoader;
    import javafx.scene.Parent;
    import javafx.scene.Scene;
    import javafx.stage.Stage;
    
    public class Main extends Application  {
    
        @Override
        public void start(Stage primaryStage) throws Exception {
            Parent root = FXMLLoader.load(getClass().getResource("view/FXMLSample.fxml"));
            Scene scene = new Scene(root, 640,480);
    
            primaryStage.setScene(scene);
            primaryStage.setTitle("User list");
            primaryStage.show();
        }
    
        public static void main(String[] args) {
            launch(args);
        }
    
    }

controller/Controller.java

package sample.controller;
    
    import java.net.URL;
    import java.util.ResourceBundle;
    
    import javafx.collections.FXCollections;
    import javafx.collections.ObservableList;
    import javafx.event.ActionEvent;
    import javafx.fxml.FXML;
    import javafx.fxml.Initializable;
    import javafx.scene.control.TableView;
    import sample.model.Person;
    import sample.model.ConnectDB;
    
    import javafx.scene.control.TableColumn;
    
    import java.sql.*;
    
    public class Controller implements Initializable {
    
        Connection conn = null;
        ResultSet rs = null;
        PreparedStatement pst = null;
    
        private ObservableList<Person> usersData = FXCollections.observableArrayList();
    
        @FXML
        private TableView<Person> tableUsers;
    
        @FXML
        private TableColumn<Person, Integer> idColumn;
    
        @FXML
        private TableColumn<Person, String> usernameColumn;
    
        @FXML
        private TableColumn<Person, String> firstnameColumn;
    
        @FXML
        private TableColumn<Person, String> lastnameColumn;
    
        @FXML
        private TableColumn<Person, String> emailColumn;
    
        @FXML
        private TableColumn<Person, String> genderColumn;
    
        @FXML
        private TableColumn<Person, String> descColumn;
    
        @FXML
        private TableColumn<Person, String> createdonColumn;
    
        @FXML
        private TableColumn<Person, String> editedonColumn;
    
        @FXML
        private TableColumn<Person, String> activeColumn;
    
        @FXML
        public void initialize(URL location, ResourceBundle resources) {
    
            conn = ConnectDB.ConnectMariaDB();
            initData();
    
            tableUsers.setItems(usersData);
    
        }
    
        private void initData(ActionEvent event) throws SQLException {
    
            String sql = "SELECT * FROM test";
            rs = pst.executeQuery(sql);
    
            if(rs.next()) {
                int id = rs.getInt("id");
                String username = rs.getString("username");
                String firstname = rs.getString("firstname");
                String lastname = rs.getString("lastname");
                String email = rs.getString("email");
                String gender = rs.getString("gender");
                String description = rs.getString("description");
                String createdon = rs.getString("createdon");
                String editedon = rs.getString("editedon");
                String active = rs.getString("active");
                usersData.add(new Person(id, username, firstname, lastname, email, gender, description, createdon, editedon, active));
            }
    
    
        }
    
    
    }

model/ConnectDB.java

package sample.model;
    
    import java.sql.*;
    
    public class ConnectDB {
    
        Connection conn = null;
    
        public static Connection ConnectMariaDB() {
            try {
                Class.forName("org.mariadb.jdbc.Driver");
                Connection conn = DriverManager.getConnection("jdbc:mariadb://localhost/test_new","root","123456");
                System.out.println("Connection success!");
                return conn;
            } catch(Exception e){
                System.out.println(e);
                return null;
            }
        }
    }

view/FXMLSample.fxml

<?xml version="1.0" encoding="UTF-8"?>
    
    <?import javafx.scene.control.*?>
    <?import javafx.scene.layout.*?>
    <?import javafx.scene.text.*?>
    
    <VBox prefHeight="400.0" prefWidth="640.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.controller.Controller">
      <children>
        <MenuBar VBox.vgrow="NEVER">
          <menus>
            <Menu mnemonicParsing="false" text="File">
              <items>
                <MenuItem mnemonicParsing="false" text="New" />
                <MenuItem mnemonicParsing="false" text="Open…" />
                <Menu mnemonicParsing="false" text="Open Recent" />
                <SeparatorMenuItem mnemonicParsing="false" />
                <MenuItem mnemonicParsing="false" text="Close" />
                <MenuItem mnemonicParsing="false" text="Save" />
                <MenuItem mnemonicParsing="false" text="Save As…" />
                <MenuItem mnemonicParsing="false" text="Revert" />
                <SeparatorMenuItem mnemonicParsing="false" />
                <MenuItem mnemonicParsing="false" text="Preferences…" />
                <SeparatorMenuItem mnemonicParsing="false" />
                <MenuItem mnemonicParsing="false" text="Quit" />
              </items>
            </Menu>
            <Menu mnemonicParsing="false" text="Edit">
              <items>
                <MenuItem mnemonicParsing="false" text="Undo" />
                <MenuItem mnemonicParsing="false" text="Redo" />
                <SeparatorMenuItem mnemonicParsing="false" />
                <MenuItem mnemonicParsing="false" text="Cut" />
                <MenuItem mnemonicParsing="false" text="Copy" />
                <MenuItem mnemonicParsing="false" text="Paste" />
                <MenuItem mnemonicParsing="false" text="Delete" />
                <SeparatorMenuItem mnemonicParsing="false" />
                <MenuItem mnemonicParsing="false" text="Select All" />
                <MenuItem mnemonicParsing="false" text="Unselect All" />
              </items>
            </Menu>
            <Menu mnemonicParsing="false" text="Help">
              <items>
                <MenuItem mnemonicParsing="false" text="About MyHelloApp" />
              </items>
            </Menu>
          </menus>
        </MenuBar>
        <AnchorPane id="AnchorPane" maxHeight="-1.0" maxWidth="-1.0" prefHeight="-1.0" prefWidth="-1.0" VBox.vgrow="ALWAYS" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/2.2">
             <children>
                <Label layoutX="20.0" layoutY="14.0" text="Table" />
                <TableView fx:id="tableUsers" layoutX="20.0" layoutY="37.0" prefHeight="285.0" prefWidth="600.0">
                  <columns>
                      <TableColumn prefWidth="42.0" text="ID" fx:id="idColumn" />
                      <TableColumn prefWidth="67.0" text="Username" fx:id="usernameColumn" />
                      <TableColumn prefWidth="156.0" text="Fullname">
                         <columns>
                            <TableColumn prefWidth="75.0" text="First name" fx:id="firstnameColumn" />
                            <TableColumn prefWidth="75.0" text="Last name" fx:id="lastnameColumn" />
                         </columns>
                      </TableColumn>
                    <TableColumn prefWidth="75.0" text="E-mail" fx:id="emailColumn" />
                    <TableColumn prefWidth="69.0" text="Gender" fx:id="genderColumn" />
                      <TableColumn prefWidth="69.0" text="Description" fx:id="descColumn" />
                      <TableColumn prefWidth="63.0" text="Created" fx:id="createdonColumn" />
                      <TableColumn minWidth="0.0" prefWidth="57.0" text="Edited" fx:id="editedonColumn" />
                      <TableColumn minWidth="4.0" prefWidth="105.0" text="Active" fx:id="activeColumn" />
                  </columns>
                </TableView>
                <Button layoutX="23.0" layoutY="336.0" mnemonicParsing="false" text="Create" />
                <Button layoutX="88.0" layoutY="336.0" mnemonicParsing="false" text="Update" />
                <Button layoutX="154.0" layoutY="336.0" mnemonicParsing="false" text="Delete" />
                <Button layoutX="219.0" layoutY="336.0" mnemonicParsing="false" text="Refresh" />
             </children>
        </AnchorPane>
      </children>
    </VBox>

error:

Error:(64, 9) java: method initData in class sample.controller.Controller cannot be applied to given types;
required: javafx.event.ActionEvent
found: no arguments
reason: actual and formal argument lists differ in length

Answer 1

I rewrote the controller as follows and everything worked.

package sample.controller;

import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import java.net.URL;
import java.util.ResourceBundle;

import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import sample.model.Person;
import sample.model.ConnectDB;

import javafx.scene.control.TableColumn;

import java.sql.*;

public class Controller implements Initializable {

    Connection conn = null;
    ResultSet rs = null;
    Statement st = null;

    @FXML
    private URL location;

    @FXML
    private ResourceBundle resources;

    @FXML
    private TableView<Person> tableUsers;

    @FXML
    private TableColumn<Person, Integer> idColumn;

    @FXML
    private TableColumn<Person, String> usernameColumn;

    @FXML
    private TableColumn<Person, String> firstnameColumn;

    @FXML
    private TableColumn<Person, String> lastnameColumn;

    @FXML
    private TableColumn<Person, String> emailColumn;

    @FXML
    private TableColumn<Person, String> genderColumn;

    @FXML
    private TableColumn<Person, String> descColumn;

    @FXML
    private TableColumn<Person, String> createdonColumn;

    @FXML
    private TableColumn<Person, String> editedonColumn;

    @FXML
    private TableColumn<Person, String> activeColumn;

    @FXML
    private void tableUsersCreate(ActionEvent event) {
        Alert alert = new Alert(AlertType.CONFIRMATION);
        alert.setTitle("Table refresh");

        // alert.setHeaderText("Results:");
        alert.setContentText("Refresh table to the database successfully!");
        tableUsers.refresh();
        alert.showAndWait();
    }

    @FXML
    private void tableUsersUpdate(ActionEvent event) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.setTitle("Table refresh");

        // alert.setHeaderText("Results:");
        alert.setContentText("Refresh table to the database successfully!");
        tableUsers.refresh();
        alert.showAndWait();
    }

    @FXML
    private void tableUsersRefresh(ActionEvent event) {
        Alert alert = new Alert(AlertType.INFORMATION);
        alert.setTitle("Table refresh");

        // alert.setHeaderText("Results:");
        alert.setContentText("Refresh table to the database successfully!");
        tableUsers.refresh();
        alert.showAndWait();
    }

    @FXML
    private void tableUsersDelete(ActionEvent event) {
        Alert alert = new Alert(AlertType.ERROR);
        alert.setTitle("Table refresh");

        // alert.setHeaderText("Results:");
        alert.setContentText("Refresh table to the database successfully!");
        tableUsers.refresh();
        alert.showAndWait();
    }

    @FXML
    public void initialize(URL location, ResourceBundle resources) {

        conn = ConnectDB.ConnectMariaDB();

        final ObservableList data = FXCollections.observableArrayList();

        String query = "SELECT * FROM test";

        Statement st = null;
        try {
            st = conn.createStatement();
        } catch (SQLException e) {
            e.printStackTrace();
        }

        ResultSet rs = null;
        try {
            rs = st.executeQuery(query);
        } catch (SQLException e) {
            e.printStackTrace();
        }

        Person person;

        try {
            while (rs.next()) {
                int id = rs.getInt("id");
                String username = rs.getString("username");
                String firstname = rs.getString("firstname");
                String lastname = rs.getString("lastname");
                String email = rs.getString("email");
                String gender = rs.getString("gender");
                String description = rs.getString("description");
                String createdon = rs.getString("createdon");
                String editedon = rs.getString("editedon");
                boolean active = rs.getBoolean("active");

                person = new Person(id,username,firstname,lastname,email,gender,description,createdon,editedon,active);
                data.add(person);
            }
            st.close();
        } catch(Exception  e) {
            System.out.println("There is an Exception.");
            System.out.println(e.getMessage());
        }
        idColumn.setCellValueFactory(new PropertyValueFactory<>("id"));
        usernameColumn.setCellValueFactory(new PropertyValueFactory<>("username"));
        firstnameColumn.setCellValueFactory(new PropertyValueFactory<>("firstname"));
        lastnameColumn.setCellValueFactory(new PropertyValueFactory<>("lastname"));
        emailColumn.setCellValueFactory(new PropertyValueFactory<>("email"));
        genderColumn.setCellValueFactory(new PropertyValueFactory<>("gender"));
        descColumn.setCellValueFactory(new PropertyValueFactory<>("description"));
        createdonColumn.setCellValueFactory(new PropertyValueFactory<>("createdon"));
        editedonColumn.setCellValueFactory(new PropertyValueFactory<>("editedon"));
        activeColumn.setCellValueFactory(new PropertyValueFactory<>("active"));

        tableUsers.setItems(data);

    }

}

Answer 2

AAA! At you business even did not reach compilation?
method

public void initialize(URL location, ResourceBundle resources)

, in it you call initData();without input arguments, which you have defined as

private void initData(ActionEvent event) throws SQLException {

. You either pass an argument in the call, or correct the method itself and remove the parameter ActionEvent event
. And finally. you shouldn't send so much code, just an error and a piece of code and a description of when and under what circumstances it occurs. With very, very rare exceptions, someone will be willing to download the entire project and compile it.