Разработка базы данных медиаплеера для организации музыки типа iTunes

Для разрешения отношение многие-ко-многим между сущностями «USERS» и «TRACK LIST» была создана таблица «SUBSCRIPTION VALIDITY», которая включает в себя дату начала подписки и её конец.

Остальные сущности отображают сущности нашей предметной области.

Стартовое окно/ Окно входа

Основная страница приложения

Окно регистрации нового пользователя

Окно персональных данных пользователя

Личный кабинет пользователя

Доказательство корректного создания нового пользователя

Добавление композиции «FALSE ALARM by THE WEEKND» в плейлист пользователя

Доказательство добавления композиции «FALSE ALARM by THE WEEKND» в плейлист пользователя

Композиция «FALSE ALARM by THE WEEKND» в БД «TRACK LIST» соответствует номеру 32

Как видно из таблицы «MY MUSIC», композиция с номером 32 действительно добавилась в плэйлист пользователя

Удаление композиции «FALSE ALARM by THE WEEKND» из плейлиста пользователя

Доказательство удаления композиции «FALSE ALARM by THE WEEKND» в плейлист пользователя

Как видно из таблицы «MY MUSIC», композиция с номером 32 действительно удалилась из плэйлиста пользователя

При этом композиция 32 никуда не пропала из таблицы «TRACK LIST»

Сортировка музыки по исполнителю «MUSE»

Сортировка музыки по исполнителю «KASABIAN»

Создадим в системе пользователя «ivanivanov@mail.ru»

Перейдем во вкладку с персональными данными этого пользователя

Теперь удалим данного пользователя при помощи кнопки «Delete user from system»

Как видно из таблицы «USERS», пользователь с номером 18 действительно удалился из списка зарегестрированых пользователей

-- Generated by Oracle SQL Developer Data Modeler 19.4.0.350.1424 --   at:        2020-06-01 16:18:08 MSK --   site:      Oracle Database 11g --   type:      Oracle Database 11g  CREATE TABLE albums (     id            VARCHAR2(5) NOT NULL,     album_name    VARCHAR2(20) NOT NULL,     release_year  DATE NOT NULL,     genre         VARCHAR2(20) NOT NULL );  ALTER TABLE albums ADD CONSTRAINT albums_pk PRIMARY KEY ( id );  CREATE TABLE my_music (     user_id    VARCHAR2(5) NOT NULL,     my_msc_id  NUMBER NOT NULL );  CREATE UNIQUE INDEX my_music__idx ON     my_music (         user_id     ASC );  ALTER TABLE my_music ADD CONSTRAINT my_msc_pk PRIMARY KEY ( my_msc_id );  CREATE TABLE performers (     id              VARCHAR2(5) NOT NULL,     performer_name  VARCHAR2(30) NOT NULL );  ALTER TABLE performers ADD CONSTRAINT performers_pk PRIMARY KEY ( id );  CREATE TABLE subscription_validity (     "Start_Date/_Start_Time"  DATE NOT NULL,     "End_Date/_End_Time"      DATE NOT NULL,     user_id                   VARCHAR2(5) NOT NULL,     track_list_id             VARCHAR2(5) NOT NULL );  ALTER TABLE subscription_validity ADD CONSTRAINT subscription_validity_pk PRIMARY KEY ( user_id,                                                                                         track_list_id );  CREATE TABLE songs (     id                  VARCHAR2(5) NOT NULL,     track_name          VARCHAR2(50) NOT NULL,     genre               VARCHAR2(20) NOT NULL,     duration            TIMESTAMP NOT NULL,     albums_id           VARCHAR2(5) NOT NULL,     performers_id       VARCHAR2(5) NOT NULL,     my_music_my_msc_id  NUMBER NOT NULL );  ALTER TABLE track_list ADD CONSTRAINT track_list_pk PRIMARY KEY ( id );  CREATE TABLE "USER" (     id                  VARCHAR2(5) NOT NULL,     password            VARCHAR2(20) NOT NULL,     name                VARCHAR2(30) NOT NULL,     email               VARCHAR2(30) NOT NULL,     phone_number        VARCHAR2(12) NOT NULL,     country             VARCHAR2(20) NOT NULL,     balance             NUMBER(7, 2),     my_music_my_msc_id  NUMBER NOT NULL );  CREATE UNIQUE INDEX user__idx ON     "USER" (         my_music_my_msc_id     ASC );  ALTER TABLE "USER" ADD CONSTRAINT user_pk PRIMARY KEY ( id );  ALTER TABLE my_music     ADD CONSTRAINT my_music_user_fk FOREIGN KEY ( user_id )         REFERENCES "USER" ( id );  ALTER TABLE subscription_validity     ADD CONSTRAINT subs_val_track_list_fk FOREIGN KEY ( track_list_id )         REFERENCES track_list ( id );  ALTER TABLE subscription_validity     ADD CONSTRAINT subs_val_user_fk FOREIGN KEY ( user_id )         REFERENCES "USER" ( id );  ALTER TABLE track_list     ADD CONSTRAINT track_list_albums_fk FOREIGN KEY ( albums_id )         REFERENCES albums ( id );  ALTER TABLE track_list     ADD CONSTRAINT track_list_my_music_fk FOREIGN KEY ( my_music_my_msc_id )         REFERENCES my_music ( my_msc_id );  ALTER TABLE track_list     ADD CONSTRAINT track_list_performers_fk FOREIGN KEY ( performers_id )         REFERENCES performers ( id );  ALTER TABLE "USER"     ADD CONSTRAINT user_my_music_fk FOREIGN KEY ( my_music_my_msc_id )         REFERENCES my_music ( my_msc_id );  CREATE SEQUENCE my_msc_my_msc_id_seq START WITH 1 NOCACHE ORDER;  CREATE OR REPLACE TRIGGER my_msc_my_msc_id_trg BEFORE     INSERT ON my_music     FOR EACH ROW     WHEN ( new.my_msc_id IS NULL ) BEGIN     :new.my_msc_id := my_msc_my_msc_id_seq.nextval; END; /  -- Oracle SQL Developer Data Modeler Summary Report:  --  -- CREATE TABLE                             6 -- CREATE INDEX                             2 -- ALTER TABLE                             13 -- CREATE VIEW                              0 -- ALTER VIEW                               0 -- CREATE PACKAGE                           0 -- CREATE PACKAGE BODY                      0 -- CREATE PROCEDURE                         0 -- CREATE FUNCTION                          0 -- CREATE TRIGGER                           1 -- ALTER TRIGGER                            0 -- CREATE COLLECTION TYPE                   0 -- CREATE STRUCTURED TYPE                   0 -- CREATE STRUCTURED TYPE BODY              0 -- CREATE CLUSTER                           0 -- CREATE CONTEXT                           0 -- CREATE DATABASE                          0 -- CREATE DIMENSION                         0 -- CREATE DIRECTORY                         0 -- CREATE DISK GROUP                        0 -- CREATE ROLE                              0 -- CREATE ROLLBACK SEGMENT                  0 -- CREATE SEQUENCE                          1 -- CREATE MATERIALIZED VIEW                 0 -- CREATE MATERIALIZED VIEW LOG             0 -- CREATE SYNONYM                           0 -- CREATE TABLESPACE                        0 -- CREATE USER                              0 --  -- DROP TABLESPACE                          0 -- DROP DATABASE                            0 --  -- REDACTION POLICY                         0 --  -- ORDS DROP SCHEMA                         0 -- ORDS ENABLE SCHEMA                       0 -- ORDS ENABLE OBJECT                       0 --  -- ERRORS                                   0 -- WARNINGS                                 0  

package sample.database;  import javafx.event.ActionEvent; import sample.model.Performers; import sample.model.TrackList; import sample.model.User;  import java.sql.*; import java.util.ArrayList;  public class DataBase {      public static void main(String[] args) {         DataBase dataBase = new DataBase();         for (TrackList t:dataBase.allMusic()              ) {             System.out.println(t.toString());         }     }     //     public boolean loginIn(String email, String password) {         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             Statement stmt = conn.createStatement();             // запрос на проверку пароля и логина (эмэил в качестве логина)             ResultSet rset = stmt.executeQuery("SELECT * FROM users u INNER JOIN subscription_validity s ON u.id_users=s.id_users where email = '" + email + "'&& password ='" + password + "'");             if (rset.next()) {                 User.setId(rset.getInt(1));                 User.setName(rset.getString(3));                 User.setEmail(rset.getString(4));                 User.setPhone(rset.getString(5));                 User.setCountry(rset.getString(6));                 User.setStartDate(rset.getString(8));                 User.setEndDate(rset.getString(9));                 return true;             }         } catch (SQLException e) {             e.printStackTrace();         }         return false;     }       public boolean emailCheck(String email) {         try {         	// подключение к db             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             // создание объекта Statement             Statement stmt = conn.createStatement();             // проверяем существует ли подобный эмэил в базе данных             ResultSet rset = stmt.executeQuery("select * from users where email = '" + email + "'");             return !rset.next();         } catch (SQLException e) {             e.printStackTrace();         }         return true;     }      public void registration(String name, String email, String phone, String password, String country, String startDate, String endDate) {         try {         	// подключение к db             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             // создание объекта Statement             Statement stmt = conn.createStatement();             // запрос на всавку данных в таблицу users нового пользователя             stmt.executeUpdate("insert into users (email,password,name,phone_num,contry) value ('" + email + "','" + password + "','" + name + "','" + phone + "','" + country + "')");             // запрос на всавку данных в таблицу subscription_validity             stmt.executeUpdate("insert into subscription_validity (Start_Date_Start_Time, End_Date_End_Time,id_users) value ('" + startDate + "','" + endDate + "', (select max(id_users) from users) )");             stmt.close();             conn.close();         } catch (SQLException e) {             e.printStackTrace();         }     }      // запрос для музыки     public ArrayList<TrackList> allMusic() {         ArrayList<TrackList> arrayList = new ArrayList<>();         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");              Statement stmt = conn.createStatement();             // запрос на вывод всех трэков с их автором и их альбомом             ResultSet rset = stmt.executeQuery("SELECT * FROM track_list t INNER JOIN performers p  ON p.id_performers=t.id_performers INNER JOIN albums a ON a.id_albums=t.id_albums");             while (rset.next()) {                 arrayList.add(new TrackList(rset.getInt(1), rset.getString(2), rset.getString(10), rset.getString(8), rset.getString(3), rset.getString(4)));             }             rset.close();             stmt.close();             conn.close();         } catch (SQLException throwables) {             throwables.printStackTrace();         }         return arrayList;     }      // запрос для музыки     public ArrayList<TrackList> myMusic(int id) {         ArrayList<TrackList> arrayList = new ArrayList<>();         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");              Statement stmt = conn.createStatement();             // запрос на вывод всех трэков с их автором и их альбомом             ResultSet rset = stmt.executeQuery("SELECT m.id_track_list, t.track_name, " +                     "a.album_name, p.performer_name, t.genre, t.duration FROM my_music m INNER JOIN " +                     "track_list t ON t.id_track_list=m.id_track_list INNER JOIN performers p ON " +                     "p.id_performers=t.id_performers INNER JOIN albums a ON a.id_albums=t.id_albums WHERE m.id_users=" + id);             while (rset.next()) {                 arrayList.add(new TrackList(rset.getInt(1), rset.getString(2), rset.getString(3), rset.getString(4), rset.getString(5), rset.getString(6)));             }             rset.close();             stmt.close();             conn.close();         } catch (SQLException throwables) {             throwables.printStackTrace();         }         return arrayList;     }      public void addMyMusic(int idUser, int idTrackList) {         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             Statement stmt = conn.createStatement();             ResultSet rset = stmt.executeQuery("SELECT * FROM my_music WHERE " +                     "id_users = " + idUser + " && id_track_list = " + idTrackList);             // сюда передаем id user, которому будет добавлять музыку             // проверяем добавляли мы уже такое или нет             if (!rset.next())                 stmt.executeUpdate("INSERT INTO my_music (id_users, id_track_list) VALUE ("+ idUser +", "+  idTrackList +")");             rset.close();             stmt.close();             conn.close();             // перед тем как добавить трэк проверяем есть ли тако         } catch (SQLException e){             e.printStackTrace();         }     }      public void deleteMyMusic(int idUser, int idTrackList) {         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             Statement stmt = conn.createStatement();             stmt.executeUpdate("DELETE FROM my_music WHERE id_users =" + idUser + "&& id_track_list =" + idTrackList);             stmt.close();             conn.close();         } catch (SQLException e){             e.printStackTrace();         }     }     // Запрос на сортировку по исполнителям     public ArrayList<Performers> performers(){         ArrayList<Performers> arrayList = new ArrayList();         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             Statement stmt = conn.createStatement();             ResultSet rset = stmt.executeQuery("SELECT * FROM performers");             while(rset.next()){                 arrayList.add(new Performers(rset.getInt(1),rset.getString(2)));             }             rset.close();             stmt.close();             conn.close();         } catch (SQLException e){             e.printStackTrace();         }         return arrayList;     }     // запрос на вывод музыки с исполнителем     public ArrayList<TrackList> performerMusic(int id) {         ArrayList<TrackList> arrayList = new ArrayList<>();         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");              Statement stmt = conn.createStatement();             // запрос на вывод всех трэков с их автором и их альбомом             ResultSet rset = stmt.executeQuery("SELECT * FROM track_list t INNER JOIN performers p  ON p.id_performers=t.id_performers INNER JOIN albums a ON a.id_albums=t.id_albums WHERE p.id_performers = " + id);             while (rset.next()) {                 arrayList.add(new TrackList(rset.getInt(1), rset.getString(2), rset.getString(10), rset.getString(8), rset.getString(3), rset.getString(4)));             }             rset.close();             stmt.close();             conn.close();         } catch (SQLException throwables) {             throwables.printStackTrace();         }         return arrayList;     }     // запрос на удаление пользователя     public void deleteUser(int idUser) {         try {             Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/my_tunes", "root", "root");             Statement stmt = conn.createStatement();             stmt.executeUpdate("DELETE FROM users WHERE id_users =" + idUser);             stmt.close();             conn.close();         } catch (SQLException e){             e.printStackTrace();         }     } } 

 package sample;  import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.stage.Modality; import javafx.stage.Stage;  public class Main extends Application {      @Override     public void start(Stage primaryStage) throws Exception{         Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/login.fxml"));         Stage newStage = new Stage();         newStage.setScene(new Scene(root));         newStage.initModality(Modality.NONE);         newStage.show();     }      public static void main(String[] args) {         launch(args);     } } 

 package sample;  import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.FXMLLoader; import javafx.fxml.Initializable; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.ComboBox; import javafx.scene.control.ListView; import javafx.stage.Modality; import javafx.stage.Stage; import sample.database.DataBase; import sample.model.Performers; import sample.model.TrackList; import sample.model.User;  import java.io.IOException; import java.net.URL; import java.util.ArrayList; import java.util.ResourceBundle;  public class Music implements Initializable {     @FXML     public ListView<TrackList> allMusic;     @FXML     public ComboBox comboBox;     @FXML     public Button myMusic;      DataBase dataBase = new DataBase();     ArrayList<TrackList> arrayList;      TrackList trackList = null;      public void addMyMusic(ActionEvent actionEvent) {     	// добавление музыки в "мой плейлист"         if(trackList != null)             dataBase.addMyMusic(User.getId(),trackList.getId());     }      @Override     public void initialize(URL location, ResourceBundle resources) {         arrayList = dataBase.allMusic();         ObservableList<TrackList> observableList = FXCollections.observableList(arrayList);          allMusic.setItems(observableList);         allMusic.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<TrackList>(){              @Override             public void changed(ObservableValue<? extends TrackList> observable, TrackList oldValue, TrackList newValue) {                 trackList = newValue;             }         });          for (Performers p:dataBase.performers()         ) {             comboBox.getItems().add(p);         }          comboBox.getItems().add(new Performers(0,"All"));         comboBox.setValue(new Performers(0,"All"));         comboBox.valueProperty().addListener(new ChangeListener<Performers>() {              @Override             public void changed(ObservableValue<? extends Performers> observable, Performers oldValue, Performers newValue) {                 if(newValue.getId() == 0) {                     arrayList = dataBase.allMusic();                     ObservableList<TrackList> observableList = FXCollections.observableList(arrayList);                     allMusic.setItems(observableList);                 } else{                     arrayList = dataBase.performerMusic(newValue.getId());                     ObservableList<TrackList> observableList = FXCollections.observableList(arrayList);                     allMusic.setItems(observableList);                 }             }         });     }      public void myMusic(ActionEvent actionEvent) {         Stage stage = (Stage) myMusic.getScene().getWindow();         stage.close();         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/mymusic.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     } } 

 package sample;  import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.FXMLLoader; import javafx.fxml.Initializable; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.ListView; import javafx.stage.Modality; import javafx.stage.Stage; import sample.database.DataBase; import sample.model.TrackList; import sample.model.User;  import javax.jws.soap.SOAPBinding; import java.io.IOException; import java.net.URL; import java.util.ArrayList; import java.util.ResourceBundle;  public class MyMusic implements Initializable {     @FXML     public ListView allMusic;     @FXML     public Button back;     @FXML     public Button userData;     DataBase dataBase = new DataBase();     ArrayList<TrackList> arrayList;     TrackList trackList = null;      public void deleteMyMusic(ActionEvent actionEvent) {         if(trackList != null)             dataBase.deleteMyMusic(User.getId(),trackList.getId());          arrayList = dataBase.myMusic(User.getId());         ObservableList<TrackList> observableList = FXCollections.observableList(arrayList);          allMusic.setItems(observableList);     }      @Override     public void initialize(URL location, ResourceBundle resources) {         arrayList = dataBase.myMusic(User.getId());         ObservableList<TrackList> observableList = FXCollections.observableList(arrayList);          allMusic.setItems(observableList);         allMusic.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<TrackList>(){              @Override             public void changed(ObservableValue<? extends TrackList> observable, TrackList oldValue, TrackList newValue) {                 trackList = newValue;             }         });     }      public void userData(ActionEvent actionEvent) {         Stage stage = (Stage) userData.getScene().getWindow();         stage.close();         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/userdata.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     }      public void back(ActionEvent actionEvent) {         Stage stage = (Stage) back.getScene().getWindow();         stage.close();         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/music.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     } } 

 package sample;  import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.PasswordField; import javafx.scene.control.TextField; import javafx.stage.Stage; import sample.database.DataBase;   public class Registration {     @FXML     public Label error;     @FXML     public Button reg;     @FXML     public TextField phone;     @FXML     public PasswordField password;     @FXML     public PasswordField repeatPassword;     @FXML     public TextField name;     @FXML     public TextField email;     @FXML     public TextField endDate;     @FXML     public TextField startDate;     @FXML     public TextField country;      public void registration(ActionEvent actionEvent) {         DataBase dataBase = new DataBase();         // String name,String email,String phone, String password, String country, String startDate, String endDate         if(name.getText().matches("[a-zA-ZРђ-РЇР°-СЏ]{3,}")){                 if(email.getText().matches("[A-Za-z0-9]{3,}[@][A-Za-z0-9]{3,}[.][A-Za-z0-9]{2,}")){                     if(phone.getText().matches("[+][7][0-9]{10}") || phone.getText().matches("[8][0-9]{10}")){                         if(dataBase.emailCheck(email.getText())){                             if(password.getText().equals(repeatPassword.getText())){                                 dataBase.registration(name.getText(),email.getText(),                                         phone.getText(),password.getText(),country.getText(), startDate.getText(), endDate.getText());                                 Stage stage = (Stage)reg.getScene().getWindow();                                 stage.close();                             }else{                                 error.setText("Пароли не совпадают");                             }                         }else{                             error.setText("Данный логин существует");                         }                     }else{                         error.setText("Введите телефон в формате +7********** или 8**********");                     }                 }else{                     error.setText("Введите emeail в формате ***@***.**");                 }         }else{             error.setText("Корректно введите имя");         }     } } 

 package sample;  import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.FXMLLoader; import javafx.fxml.Initializable; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.stage.Modality; import javafx.stage.Stage; import sample.database.DataBase; import sample.model.User;  import java.io.IOException; import java.net.URL; import java.util.ResourceBundle;  public class Userdata implements Initializable {     @FXML     public Label name;     @FXML     public Label email;     @FXML     public Label phone;     @FXML     public Label contry;     @FXML     public Label startDate;     @FXML     public Label endDate;     @FXML     public Button back;     @FXML     public Button delete;      @Override     public void initialize(URL location, ResourceBundle resources) {         name.setText(User.getName());         email.setText(User.getEmail());         phone.setText(User.getPhone());         contry.setText(User.getCountry());         startDate.setText(User.getStartDate());         endDate.setText(User.getEndDate());     }      public void back(ActionEvent actionEvent) {         Stage stage = (Stage) back.getScene().getWindow();         stage.close();         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/mymusic.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     }      public void delete(ActionEvent actionEvent) {         DataBase dataBase = new DataBase();         dataBase.deleteUser(User.getId());          Stage stage = (Stage) delete.getScene().getWindow();         stage.close();         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/login.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     } } 

 package sample.model;  public class Performers {     private int id;     private String name;      public Performers(int id, String name) {         this.id = id;         this.name = name;     }      @Override     public String toString() {         return name;     }      public int getId() {         return id;     }      public void setId(int id) {         this.id = id;     }      public String getName() {         return name;     }      public void setName(String name) {         this.name = name;     } } 

 package sample.model;  public class TrackList {     private int id;     private String trackName;     private String albumName;     private String performerName;     private String genre;     private String duration;      public TrackList(int id, String trackName, String albumName, String performerName, String genre, String duration) {         this.id = id;         this.trackName = trackName;         this.albumName = albumName;         this.performerName = performerName;         this.genre = genre;         this.duration = duration;     }      public int getId() {         return id;     }      public void setId(int id) {         this.id = id;     }      public String getTrackName() {         return trackName;     }      public void setTrackName(String trackName) {         this.trackName = trackName;     }      public String getAlbumName() {         return albumName;     }      public void setAlbumName(String albumName) {         this.albumName = albumName;     }      public String getPerformerName() {         return performerName;     }      public void setPerformerName(String performerName) {         this.performerName = performerName;     }      public String getGenre() {         return genre;     }      public void setGenre(String genre) {         this.genre = genre;     }      public String getDuration() {         return duration;     }      public void setDuration(String duration) {         this.duration = duration;     }      @Override     public String toString() {         return                 trackName +                 " by " + performerName  +                 " from album - " + albumName +                 " (" + genre + ") " +                 ", " + duration;     }   } 

 package sample.model;  public class User {     private static int id;     private static String name;     private static  String email;     private static String phone;     private static String country;      private static String startDate;     private static String endDate;      public static int getId() {         return id;     }      public static void setId(int id) {         User.id = id;     }      public static String getName() {         return name;     }      public static void setName(String name) {         User.name = name;     }      public static String getEmail() {         return email;     }      public static void setEmail(String email) {         User.email = email;     }      public static String getPhone() {         return phone;     }      public static void setPhone(String phone) {         User.phone = phone;     }      public static String getCountry() {         return country;     }      public static void setCountry(String country) {         User.country = country;     }      public static String getStartDate() {         return startDate;     }      public static void setStartDate(String startDate) {         User.startDate = startDate;     }      public static String getEndDate() {         return endDate;     }      public static void setEndDate(String endDate) {         User.endDate = endDate;     } } 

 package sample;  import javafx.event.ActionEvent; import javafx.fxml.FXML; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.control.PasswordField; import javafx.scene.control.TextField; import javafx.stage.Modality; import javafx.stage.Stage; import sample.database.DataBase;  import java.io.IOException;  public class Login {     @FXML     public Button loginIn;     @FXML     public Button registration;     @FXML     public TextField email;     @FXML     public PasswordField password;     @FXML     public Label error;      public void loginIn(ActionEvent actionEvent) {         DataBase dataBase = new DataBase();         if(email.getText() != null ){             if(password.getText() != null){                 if(dataBase.loginIn(email.getText(), password.getText())){                     Stage stage = (Stage) loginIn.getScene().getWindow();                     stage.close();                     try {                         Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/music.fxml"));                         Stage newStage = new Stage();                         newStage.setScene(new Scene(root));                         newStage.initModality(Modality.NONE);                         newStage.show();                     } catch (IOException e) {                         e.printStackTrace();                     }                 } else {                     error.setText("This Login or Password does not exist");                 }             } else {                 error.setText("Please, enter your Password: ");             }         } else {             error.setText("Please, enter your Login: ");         }     }      public void registration(ActionEvent actionEvent) {         try {             Parent root = FXMLLoader.load(getClass().getResource("/sample/fxml/registration.fxml"));             Stage newStage = new Stage();             newStage.setScene(new Scene(root));             newStage.initModality(Modality.NONE);             newStage.show();         } catch (IOException e) {             e.printStackTrace();         }     } }