JavaFx Sqlite Database Tutorial 5 - How to show and hide a window in Jav...

package application;

import java.io.IOException;
import java.net.URL;
import java.sql.SQLException;
import java.util.ResourceBundle;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class LoginController implements Initializable {
 public LoginModel loginModel = new LoginModel();
 
 
   @FXML
   private Label isConnected;
   
   @FXML
   private TextField txtUsername;
   
   @FXML
   private TextField txtPassword;
 @Override
 public void initialize(URL location, ResourceBundle resources) {
  // TODO Auto-generated method stub
  if (loginModel.isDbConnected()) {
   isConnected.setText("Connected");
  } else {

   isConnected.setText("Not Connected");
  }
 }
 
 public void Login (ActionEvent event) {
  try {
   if (loginModel.isLogin(txtUsername.getText(), txtPassword.getText())) {
    isConnected.setText("username and password is correct");
    ((Node)event.getSource()).getScene().getWindow().hide();
    Stage primaryStage = new Stage();
    FXMLLoader loader = new FXMLLoader();
    Pane root = loader.load(getClass().getResource("/application/User.fxml").openStream());
    UserController userController = (UserController)loader.getController();
    userController.GetUser(txtUsername.getText());
    Scene scene = new Scene(root);
    scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
    primaryStage.setScene(scene);
    primaryStage.show();
    
    
   } else {
    isConnected.setText("username and password is not correct");
   }
  } catch (SQLException e) {
   isConnected.setText("username and password is not correct");
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
  
}

package application;
import java.sql.*;
public class LoginModel {
  Connection conection;
  public LoginModel () {
   conection = SqliteConnection.Connector();
   if (conection == null) {

   System.out.println("connection not successful");
    System.exit(1);}
  }
  
  public boolean isDbConnected() {
   try {
  return !conection.isClosed();
 } catch (SQLException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
  return false;
 }
}
  public boolean isLogin(String user, String pass) throws SQLException {
   PreparedStatement preparedStatement = null;
   ResultSet resultSet = null;
   String query = "select * from employee where username = ? and password = ?";
   try {    
    preparedStatement = conection.prepareStatement(query);
    preparedStatement.setString(1, user);
    preparedStatement.setString(2, pass);
    
    resultSet = preparedStatement.executeQuery();
    if (resultSet.next()) {
     return true;
    } 
    else {
     return false;
    }
  
 } catch (Exception e) {
    return false;
  // TODO: handle exception
 } finally {
  preparedStatement.close();
  resultSet.close();
 }
  }
}

package application;
 
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.stage.Stage;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
 

public class Main extends Application {
 @Override
 public void start(Stage primaryStage) {
  try {
   Parent root = FXMLLoader.load(getClass().getResource("/application/Login.fxml"));
   Scene scene = new Scene(root);
   scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
   primaryStage.setScene(scene);
   primaryStage.show();
  } catch(Exception e) {
   e.printStackTrace();
  }
 }
 
 public static void main(String[] args) {
  launch(args);
 }
}

package application;
import java.sql.*;
public class SqliteConnection {
  public static Connection Connector() {
 try {
  Class.forName("org.sqlite.JDBC");
  Connection conn =DriverManager.getConnection("jdbc:sqlite:EmployeeDb.sqlite");
  return conn;
 } catch (Exception e) {
  System.out.println(e);
  return null;
  // TODO: handle exception
 }
}
}

package application;

import java.net.URL;
import java.util.ResourceBundle;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class UserController implements Initializable {
    @FXML
    private Label userLbl;
 @Override
 public void initialize(URL location, ResourceBundle resources) {
  // TODO Auto-generated method stub
  
 }
 
 public void GetUser(String user) {
  // TODO Auto-generated method stub
  userLbl.setText(user);
 }
 
 public void SignOut(ActionEvent event) {
  try {
   ((Node)event.getSource()).getScene().getWindow().hide();
   Stage primaryStage = new Stage();
   FXMLLoader loader = new FXMLLoader();
   Pane root = loader.load(getClass().getResource("/application/Login.fxml").openStream());
   
   Scene scene = new Scene(root);
   scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
   primaryStage.setScene(scene);
   primaryStage.show();
  } catch (Exception e) {
   // TODO: handle exception
  }
 }

}

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.text.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane prefHeight="302.0" prefWidth="367.0" xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.LoginController">
   <children>
      <Label fx:id="isConnected" layoutY="35.0" prefHeight="46.0" prefWidth="367.0" text="Status" textFill="#cd1313">
         <font>
            <Font size="18.0" />
         </font>
      </Label>
      <TextField fx:id="txtUsername" layoutX="54.0" layoutY="108.0" promptText="User Name">
         <font>
            <Font size="18.0" />
         </font>
      </TextField>
      <PasswordField fx:id="txtPassword" layoutX="54.0" layoutY="157.0" promptText="Password">
         <font>
            <Font size="18.0" />
         </font>
      </PasswordField>
      <Button layoutX="103.0" layoutY="216.0" mnemonicParsing="false" onAction="#Login" text="Login">
         <font>
            <Font size="18.0" />
         </font>
      </Button>
   </children>
</AnchorPane>

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.40" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.UserController">
   <top>
      <HBox BorderPane.alignment="CENTER">
         <children>
            <Label fx:id="userLbl" prefHeight="34.0" prefWidth="106.0" text="User Welcome" />
            <Button mnemonicParsing="false" onAction="#SignOut" prefHeight="28.0" prefWidth="103.0" text="Sign Out" />
         </children>
      </HBox>
   </top>
</BorderPane>