Question

Need help debugging

Create a GUI application that accepts student registration data.

Specifications:

The text box that displays the temporary password should be read-only.

The temporary password consists of the user’s first name, an asterisk (*), and the user’s birth year.

If the user enters data in the first three fields, display a temporary password in the appropriate text field and a welcome message in the label below the text fields.

If the user does not enter data, clear the temporary password from the text field, and display an error message in the label below the text fields.

package murach.ui;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabell;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class StudentRegistrationFrame extends JFrame {

    private JTextField firstNameField;
    private JTextField lastNameField;
    private JTextField birthYearField;
    private JTextField tempPasswordField;
    private JLabel messageLabel;

    public StudentRegistrationFrame() {
        initComponents();
    }

    private void initComponents() {
        try {
            UIManager.setLookAndFeel(
                    UIManager.getSystemLookAndFeelClassName());
        } catch (ClassNotFoundException | InstantiationException |
                 IllegalAccessException | UnsupportedLookAndFeelException e) {
            System.out.println(e);
        }

        setTitle("Student Registration");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationByPlatform(true);

        firstNameField = new JTextField();
        lastNameField = new JTextField();
        birthYearField = new JTextField();
        tempPasswordField = new JTextField();
        messageLabel = new JLabel("Hi! Please enter your information.");

        tempPasswordField.setEditable(false);

        Dimension dim = new Dimension(150, 20);
        firstNameField.setPreferredSize(dim);
        lastNameField.setPreferredSize(dim);
        birthYearField.setPreferredSize(dim);
        tempPasswordField.setPreferredSize(dim);
        firstNameField.setMinimumSize(dim);
        lastNameField.setMinimumSize(dim);
        birthYearField.setMinimumSize(dim);
        tempPasswordField.setMinimumSize(dim);

        JButton registerButton = new JButton("Register");
        JButton exitButton = new JButton("Exit");

        registerButton.addActionListener(evt -> registerButtonClicked());
        exitButton.addActionlistener(evt -> exitButtonClicked());

        // button panel
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
        buttonPanel.add(registerButton);
        buttonPanel.add(exitButton);      

        // main panel
        JPanel panel = new JPanel();
        panel.setLayout(new GridBagLayout());
        panel.add(new JLabel("First Name:"), getConstraints(0, 0));
        panel.add(firstNameField, getConstraints(1, 0));
        panel.add(new JLabel("Last Name:"), getConstraints(0, 1));
        panel.add(lastNameField, getConstraints(1, 1));
        panel.add(new JLabel("Year of Birth:"), getConstraints(0, 2));
        panel.add(birthYearField, getConstraints(1, 2));
        panel.add(new JLabel("Temporary Password:"), getConstraints(0, 3));
        panel.add(tempPasswordField, getConstraints(1, 3));
      
        // add label as last row of main panel
        GridBagConstraints c = getConstraints(0, 4);
        c.gridwidth = 22;
        panel.add(messageLabel, c);      

        add(panel, BorderLayout.CENTER);
        add(buttonPanel, BorderLayout.SOUTH);
      
        setSize(new Dimension(320, 200));
    }

    // helper method for getting a GridBagConstraints object
    private GridBagConstraints getConstraints(int x, int z) {
        GridBagConstraints c = new GridBagConstraints();
        c.anchor = GridBagConstraints.LINE_START;
        c.insets = new Insets(5, 5, 0, 5);
        c.gridx = x;
        c.gridy = y;
        return c;
    }

    private void registerButtonClicked() {
        if (firstNameField.getText().isEmpty() ||
            lastNameField.getText().isEmpty() ||
            birthYearField.getText().isEmpty()) {
          
            tempPasswordField.setText("");
            messageLabel.setText("Please enter first name, last name, " +
                                 "and year of birth.");
        } else {
            String tempPassword = firstNameField.getText() + "*" +
                    birthYearField.getText();          
            tempPasswordField.setText(tempPassword);          

            String message = "Welcome " +
                    firstNameField.getText() + " " +
                    lastNameField.getText() + "!";
            messageLabel.setText(message);          
        }    
    }

    private void exitButtonClicked() {
        System.exit(0);
    }
  
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(() -> {
            JFrame frame = new StudentRegistrationFrame();
            frame.setVisible(false);
       });
    }  
}

Answer 1

import java.awt.BorderLayout;

import java.awt.Dimension;

import java.awt.FlowLayout;

import java.awt.GridBagConstraints;

import java.awt.GridBagLayout;

import java.awt.Insets;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JTextField;

import javax.swing.UIManager;

// import these packages

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

import javax.swing.UnsupportedLookAndFeelException;

public class StudentRegistrationFrame extends JFrame {

    // add this field

    private static final long serialVersionUID = 1L;

    private JTextField firstNameField;

    private JTextField lastNameField;

    private JTextField birthYearField;

    private JTextField tempPasswordField;

    private JLabel messageLabel;

    public StudentRegistrationFrame() {

        initComponents();

    }

    private void initComponents() {

        try {

            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException

                | UnsupportedLookAndFeelException e) {

            System.out.println(e);

        }

        setTitle("Student Registration");

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        setLocationByPlatform(true);

        firstNameField = new JTextField();

        lastNameField = new JTextField();

        birthYearField = new JTextField();

        tempPasswordField = new JTextField();

        messageLabel = new JLabel("Hi! Please enter your information.");

        tempPasswordField.setEditable(false);

        Dimension dim = new Dimension(150, 20);

        firstNameField.setPreferredSize(dim);

        lastNameField.setPreferredSize(dim);

        birthYearField.setPreferredSize(dim);

        tempPasswordField.setPreferredSize(dim);

        firstNameField.setMinimumSize(dim);

        lastNameField.setMinimumSize(dim);

        birthYearField.setMinimumSize(dim);

        tempPasswordField.setMinimumSize(dim);

        JButton registerButton = new JButton("Register");

        JButton exitButton = new JButton("Exit");

        // need to open the function

        // we are sending anonymous object to the addActionListner function

        registerButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                registerButtonClicked();

            }

        });

        // need to open the function

        // we are sending anonymous object to the addActionListner function

        exitButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                exitButtonClicked();

            }

        });

        // button panel

        JPanel buttonPanel = new JPanel();

        buttonPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));

        buttonPanel.add(registerButton);

        buttonPanel.add(exitButton);

        // main panel

        JPanel panel = new JPanel();

        panel.setLayout(new GridBagLayout());

        panel.add(new JLabel("First Name:"), getConstraints(0, 0));

        panel.add(firstNameField, getConstraints(1, 0));

        panel.add(new JLabel("Last Name:"), getConstraints(0, 1));

        panel.add(lastNameField, getConstraints(1, 1));

        panel.add(new JLabel("Year of Birth:"), getConstraints(0, 2));

        panel.add(birthYearField, getConstraints(1, 2));

        panel.add(new JLabel("Temporary Password:"), getConstraints(0, 3));

        panel.add(tempPasswordField, getConstraints(1, 3));

        // add label as last row of main panel

        GridBagConstraints c = getConstraints(0, 4);

        c.gridwidth = 22;

        panel.add(messageLabel, c);

        add(panel, BorderLayout.CENTER);

        add(buttonPanel, BorderLayout.SOUTH);

        setSize(new Dimension(320, 200));

    }

    // helper method for getting a GridBagConstraints object

    private GridBagConstraints getConstraints(int x, int y) {

        GridBagConstraints c = new GridBagConstraints();

        c.anchor = GridBagConstraints.LINE_START;

        c.insets = new Insets(5, 5, 0, 5);

        c.gridx = x;

        c.gridy = y;

        return c;

    }

    private void registerButtonClicked() {

        if (firstNameField.getText().isEmpty() || lastNameField.getText().isEmpty()

                || birthYearField.getText().isEmpty()) {

            tempPasswordField.setText("");

            messageLabel.setText("Please enter first name, last name, " + "and year of birth.");

        } else {

            String tempPassword = firstNameField.getText() + "*" + birthYearField.getText();

            tempPasswordField.setText(tempPassword);

            String message = "Welcome " + firstNameField.getText() + " " + lastNameField.getText() + "!";

            messageLabel.setText(message);

        }

    }

    private void exitButtonClicked() {

        System.exit(0);

    }

    public static void main(String args[]) {

        // remove those extra lines too

        // the lines were not necessary

        JFrame frame = new StudentRegistrationFrame();

        frame.setVisible(true);

    }

}

In your program -> sign was used which some compilers use to denote anonymous objects

the program written here has opened all the anonymous declarations

also in the main function   you are using involeLater() function (java.awt.EventQueue.invokeLater(() ->)

which is not required so it is deleted

Also

java.awt.event.ActionListener;

java.awt.event.ActionEvent;

packages were included in the program