Hi, I have problem
I can't add to the JTable new row (public void addRow(ArrayList<Object> newRow)) from the other class with action of the button
Main.java

import com.sun.javaws.Globals;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import javax.swing.event.TableModelEvent;
import javax.swing.table.AbstractTableModel;
import javax.xml.bind.annotation.XmlElementDecl;

public class Main extends GuiClass{
    public static int cols;
    public static void main(String[] args) {


        DbLcDutConnection connection = new DbLcDutConnection();
        String query = "SELECT * FROM students";
        try {
            Statement statement = connection.getConnection().createStatement();
            ResultSet resultSet = statement.executeQuery(query);
            ResultSetMetaData counter = resultSet.getMetaData();
            cols=counter.getColumnCount();
            GuiClass gui = new GuiClass();
            gui.startGui("ЛК ДУТ");
            resultSet.beforeFirst();
            while (resultSet.next()){
                int row=resultSet.getRow();
                gui.addToTable(counter.getColumnCount(), resultSet, row-1);
            }

            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }
    //Search
    public Main() {

    }
}
class MyModel extends AbstractTableModel {

    static ArrayList<ArrayList<Object>> list = new ArrayList<ArrayList<Object>>();
    public int getColumnCount() {
        return Main.cols;
    }
    public String getColumnName(int column){
        switch (column) {
            case 0:
                return "Id";
            case 1:
                return "Pib";
            case 2:
                return "Speciality";
            case 3:
                return "Date of birth";
            case 4:
                return "Address";
            case 5:
                return "Phone";
        }
        return "";
    }
    public int getRowCount() {
        return list.size();
    }

    public Object getValueAt(int r, int c) {
        return list.get(r).get(c);
    }

    public void setValueAt(Object obj, int r, int c) {
        ArrayList<Object> rowArray = new ArrayList<Object>();
        rowArray.add(obj);
        try {
            list.get(r).add(rowArray);
        }catch (Exception e){
            list.add(new ArrayList<Object>());
            list.get(r).add(rowArray);
        }
        fireTableCellUpdated(r, c);
    }
    public void addRow(ArrayList<Object> newRow) {
        System.out.println(1);
        int rowCount = getRowCount();
        list.add(new ArrayList<Object>());
        for(int i=0; i<newRow.size(); i++){
            list.get(rowCount).add(newRow.get(i));
        }
        fireTableRowsInserted(rowCount, rowCount);
    }
}

GuiClass.java

import javax.swing.*;
import javax.swing.border.TitledBorder;
import javax.swing.table.AbstractTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import java.util.ArrayList;

public class GuiClass {
//    final AbstractTableModel model = new MyModel();
    MyModel model = new MyModel();
    String specialities [] = {"Обслуговування компютерних систем і мереж",
            "Монтаж, обслуговування та експлуатація апаратних засобів інформатизації",
            "Технічне обслуговування і ремонт апаратури зв’язку та оргтехніки",
            "Монтаж, обслуговування і ремонт станційного обладнання електрозв’язку"};
    String specializations [] = {"Компютерна інженерія", "Телекомунікації"};


    JLabel specialityLabel;
    JLabel specializationLabel;
    JComboBox specialityComboBox;
    JComboBox specializatonComboBox;
    JPanel studentSearchPanel;
    JPanel specPanel;
    JTextField searchStudentTextField;
    JLabel searchStudentLabel;
    JMenuBar menuBar;
    JMenu menuFile;
    JMenu menuOperations;
    JMenu menuReports;
    JMenuItem openItem;
    JMenuItem  saveItem;
    JMenuItem saveAsItem;
    public JTable mainStudentsTable= new JTable(model);
    JScrollPane mainStudentsTableScrollPane;
    JPanel registerStudentPanel;
    JButton registerStudentButton;
    JPanel tablePanel;


    public void startGui(String nameOfForm){
        JFrame frame = new JFrame();
        frame.setTitle(nameOfForm);
        frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
//        frame.setUndecorated(true);
//        frame.setAlwaysOnTop(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        frame.setLayout(new BorderLayout());
        frame.setLocationRelativeTo(null);
        frame.setResizable(true);
        frame.setCursor(new Cursor(Cursor.HAND_CURSOR));

        // НАЛАШТУВАННЯ ФРЕЙМА


         specialityLabel = new JLabel("Спеціальність: ");
         specializationLabel = new JLabel("Спеціалізація: ");
         specialityComboBox = new JComboBox(specialities);
         specializatonComboBox = new JComboBox(specializations);
         studentSearchPanel = new JPanel();
         searchStudentTextField = new JTextField(20);
         searchStudentLabel = new JLabel("ПІБ     ");
         specPanel = new JPanel();
         menuBar = new JMenuBar();
         menuFile = new JMenu("File");
         menuOperations = new JMenu("Operations");
         menuReports = new JMenu("Reports");
        menuBar.add(menuFile);
        menuBar.add(menuOperations);
        menuBar.add(menuReports);
         openItem = new JMenuItem("Open");
         saveItem = new JMenuItem("Save");
         saveAsItem = new JMenuItem("Save as");
        menuFile.add(openItem);
        menuFile.add(saveItem);
        menuFile.add(saveAsItem);
        frame.setJMenuBar(menuBar);
         mainStudentsTableScrollPane = new JScrollPane(mainStudentsTable, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
        mainStudentsTableScrollPane.setSize(400,400);
//        mainStudentsTable = new JTable(Main.studentsTableModel);
        registerStudentPanel = new JPanel(new BorderLayout());
        registerStudentButton = new JButton("Додати нового студента");
        registerStudentButton.addActionListener(new StudentRegisterActionListener());
        mainStudentsTableScrollPane.setPreferredSize(new Dimension(200,260));
        tablePanel = new JPanel(new BorderLayout());
        // СТВОРЕНІ КОМПОНЕНТИ

        specPanel.setLayout(new GridBagLayout());
        specPanel.add(specialityLabel, new GridBagConstraints(0, 0, 1, 1, 1, 1, GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(1, 40, 1, 1), 0, 0));
        specPanel.add(specialityComboBox, new GridBagConstraints(1,0,1,1,1,1,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,450),0,0));
        specPanel.add(specializationLabel, new GridBagConstraints(0,1,1,1,1,1,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(1,40,1,1),0,0));
        specPanel.add(specializatonComboBox, new GridBagConstraints(1,1,1,1,1,1,GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,450),0,0));
        specPanel.setBackground(Color.GREEN);
        // ПАНЕЛЬ СПЕЦІАЛІЗАЦІЙ І СПЕЦІАЛЬНОСТЕЙ

        studentSearchPanel.setLayout(new BorderLayout());
        studentSearchPanel.setBorder(new TitledBorder("Пошук студента"));
        studentSearchPanel.add(searchStudentLabel, BorderLayout.NORTH);
        studentSearchPanel.add(searchStudentTextField, BorderLayout.NORTH);
        //ПАНЕЛЬ ПОШУКУ СТУДЕНТІВ

        tablePanel.add(mainStudentsTableScrollPane, BorderLayout.CENTER);

        frame.add(tablePanel, BorderLayout.SOUTH);
        frame.add(specPanel, BorderLayout.NORTH);
        frame.add(registerStudentPanel, BorderLayout.EAST);
        frame.add(studentSearchPanel, BorderLayout.WEST);
        registerStudentPanel.add(registerStudentButton, BorderLayout.SOUTH);
        StudentRegisterActionListener studentReg=new StudentRegisterActionListener();
//        StudentRegisterActionListener.regButton.addActionListener(new ActionListener() {
//            public void actionPerformed(ActionEvent e) {
//                    ArrayList<Object> newRow=new ArrayList<Object>();
//                    newRow.add(studentReg.name.getText());
//                    newRow.add(2);
//                    newRow.add(3);
//                    newRow.add(4);
//                    newRow.add(5);
//                    newRow.add(6);
//                    model.addRow(newRow);
//            }
//        });
    }
    public void addToTable(int x, ResultSet resultSet, int row) {
        for (int i = 1; i <= x; i++) {
            try {
                model.setValueAt(resultSet.getObject(i), row, i-1);
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    public String[] getSpecialities() {
        return specialities;
    }public String[] getSpecializations() {
        return specializations;
    }
}

In this class I am doing actiolistner and all is good , but if I do it here I have problem: 106.-117.
StudentRegister.class

import com.mysql.fabric.jdbc.FabricMySQLDriver;

import javax.lang.model.element.Name;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.util.ArrayList;

class StudentRegisterActionListener extends GuiClass implements ActionListener{

    GuiClass gui = new GuiClass();
    JTextField name = new JTextField(30);
    JTextField dateOfBirth = new JTextField(30);
    JTextField address = new JTextField(30);
    JTextField phone = new JTextField(30);
    JLabel nameLabel = new JLabel("ПІБ: ");
    JLabel dateOfBirthLabel = new JLabel("Дата народження");
    JLabel addressLabel = new JLabel("Адреса");


        public JComboBox getSpecialityComboBox() {
            return specialityComboBox;
        }


        JLabel phoneLabel = new JLabel("Номер телефону");
        JComboBox specialityComboBox = new JComboBox(gui.getSpecialities());
        JComboBox specializationsComboBox = new JComboBox(gui.getSpecializations());
        JLabel specialityLabel = new JLabel("Оберіть спеціальіність");
        JLabel specializationsLabel = new JLabel("Оберіть спеціалізацію");
        static JButton regButton= new JButton("Реєстрація");

        public JTextField getName() {
            return name;
        }

        public JTextField getDateOfBirth() {
            return dateOfBirth;
        }

        public JTextField getAddress() {
            return address;
        }

        public JTextField getPhone() {
            return phone;
        }

        @Override
    public void actionPerformed(ActionEvent e) {
            mainStudentsTable = new JTable(model);

        final JFrame registerStudent = new JFrame("Реєстрація");
            registerStudent.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            registerStudent.setLocationRelativeTo(null);
            registerStudent.setLayout(new GridBagLayout());
            registerStudent.setSize(350,250);
            registerStudent.setVisible(true);

        registerStudent.add(nameLabel, new GridBagConstraints(0,0,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(name, new GridBagConstraints(1,0,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(dateOfBirthLabel, new GridBagConstraints(0,1,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(dateOfBirth, new GridBagConstraints(1,1,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(addressLabel, new GridBagConstraints(0,2,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(address, new GridBagConstraints(1,2,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(phoneLabel, new GridBagConstraints(0,3,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(phone, new GridBagConstraints(1,3,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(specialityLabel, new GridBagConstraints(0,4,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(specialityComboBox, new GridBagConstraints(1,4,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(specializationsLabel, new GridBagConstraints(0,5,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(specializationsComboBox, new GridBagConstraints(1,5,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.add(regButton, new GridBagConstraints(2,6,1,1,1,1,GridBagConstraints.NORTH, GridBagConstraints.HORIZONTAL, new Insets(1,1,1,1),0,0));
        registerStudent.setLocationRelativeTo(null);
            registerStudent.pack();
            regButton.addActionListener(new ActionListener() {

//                private final String URL = "jdbc:mysql://localhost:3306/lc_dut_test_db";
//                private final String USERNAME = "root";
//                private final String PASSWORD = "vladik0555";
                private String query1 = "INSERT INTO students(pib, Speciality, date_of, adress, phone) VALUES(?,?,?,?,?)";
                PreparedStatement preparedStatement;
                Connection connection;
                @Override
                public void actionPerformed(ActionEvent e) {

                    try {
                        Driver driver = new FabricMySQLDriver();
                        DriverManager.registerDriver(driver);
                        connection = DriverManager.getConnection(DbLcDutConnection.URL, DbLcDutConnection.USERNAME, DbLcDutConnection.PASSWORD);
                        preparedStatement = connection.prepareStatement(query1);

                        preparedStatement.setString(1, name.getText());
                        preparedStatement.setString(2, (String) specialityComboBox.getSelectedItem());
                        preparedStatement.setString(3, dateOfBirth.getText());
                        preparedStatement.setString(4, address.getText());
                        preparedStatement.setString(5, phone.getText());

                        preparedStatement.execute();

                        name.setText("");
                        dateOfBirth.setText("");
                        address.setText("");
                        phone.setText("");
//                        mainStudentsTable.setModel(model);
                        ArrayList<Object> newRow=new ArrayList<Object>();
                        newRow.add(name.getText());
                        newRow.add(2);
                        newRow.add(3);
                        newRow.add(4);
                        newRow.add(5);
                        newRow.add(6);
                        model.addRow(newRow);
                        registerStudent.dispose();

                        preparedStatement.close();


                    } catch (SQLException e1) {
                        e1.printStackTrace();
                    }

                }

            });




    }
}

Try this:

Object[] row = {"Data 1","Data 2","Data 3","Data 4"};

            DefaultTableModel model = (DefaultTableModel) jTable1.getModel();

        model.addRow(row);
Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.