All parts completed in JavaSwingSimpleExercise.

part-1/E1.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class ClickCounterApp extends JFrame implements ActionListener {
+    private JLabel counterLabel;    // Displays the click count
+    private JButton clickButton;    // Button to register clicks
+    private int count = 0;          // Stores the current count
+
+    public ClickCounterApp() {
+        setTitle("Click Counter");
+        counterLabel = new JLabel("Clicks: 0", SwingConstants.CENTER);
+        clickButton = new JButton("Click Me");
+        clickButton.addActionListener(this);
+        setSize(500, 300);
+        setLayout(new BorderLayout());
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        add(counterLabel, BorderLayout.CENTER);
+        add(clickButton, BorderLayout.SOUTH);
+    }
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        count++;  // Increment the click counter
+        counterLabel.setText("Clicks: " + count);
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> new ClickCounterApp().setVisible(true));
+    }
+}

part-2/E2.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class GreetingFormApp extends JFrame implements ActionListener {
+    private JTextField nameField;   // Field for user input
+    private JButton greetButton;    // Button to trigger greeting
+    private JLabel messageLabel;    // Label to display greeting
+
+    public GreetingFormApp() {
+        setTitle("Greeting Form");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(500, 300);
+        nameField = new JTextField(15);
+        greetButton = new JButton("Greet");
+        messageLabel = new JLabel("Enter your name and press Greet.", SwingConstants.CENTER);
+
+        greetButton.addActionListener(this);
+
+        JPanel inputPanel = new JPanel();
+        inputPanel.add(new JLabel("Name:"));
+        inputPanel.add(nameField);
+        inputPanel.add(greetButton);
+
+        setLayout(new BorderLayout());
+        add(inputPanel, BorderLayout.NORTH);
+        add(messageLabel, BorderLayout.CENTER);
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        String name = nameField.getText().trim();
+        if (name.isEmpty()) {
+            messageLabel.setText("Please enter a name.");
+        } else {
+            messageLabel.setText("Hello, " + name + "!");
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> new GreetingFormApp().setVisible(true));
+    }
+}

part-3/E3.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class ThemeColorSelectorApp extends JFrame implements ActionListener {
+    private JPanel mainPanel;      // The panel whose background will change
+    private JButton redButton;     // Button to select red theme
+    private JButton greenButton;   // Button to select green theme
+    private JButton blueButton;    // Button to select blue theme
+
+    public ThemeColorSelectorApp() {
+        setTitle("Theme Color Selector");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(500, 400);
+        mainPanel = new JPanel();
+
+        redButton = new JButton("Red");
+        greenButton = new JButton("Green");
+        blueButton = new JButton("Blue");
+
+        redButton.setActionCommand("RED");
+        greenButton.setActionCommand("GREEN");
+        blueButton.setActionCommand("BLUE");
+
+        redButton.addActionListener(this);
+        greenButton.addActionListener(this);
+        blueButton.addActionListener(this);
+
+        JPanel buttonPanel = new JPanel();
+        buttonPanel.add(redButton);
+        buttonPanel.add(greenButton);
+        buttonPanel.add(blueButton);
+
+        setLayout(new BorderLayout());
+        add(buttonPanel, BorderLayout.NORTH);
+        add(mainPanel, BorderLayout.CENTER);
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        switch (e.getActionCommand()) {
+            case "RED":   mainPanel.setBackground(Color.RED);   break;
+            case "GREEN": mainPanel.setBackground(Color.GREEN); break;
+            case "BLUE":  mainPanel.setBackground(Color.BLUE);  break;
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> new ThemeColorSelectorApp().setVisible(true));
+    }
+}

part-4/E4.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionListener;
+import java.awt.event.ActionEvent;
+
+public class RegistrationFormApp extends JFrame implements ActionListener {
+    private JTextField txtName;           // User name input
+    private JTextField txtEmail;          // User email input
+    private JPasswordField txtPassword;   // Password input
+    private JRadioButton rbMale, rbFemale;  // Gender selection
+    private JCheckBox cbJava, cbPython, cbCpp;  // Interests selection
+    private JButton btnSubmit;            // Submit form button
+    private GridBagConstraints gbc;       // Layout constraints
+
+    public RegistrationFormApp() {
+        setTitle("User Registration");
+        setSize(500, 350);
+        setDefaultCloseOperation(EXIT_ON_CLOSE);
+        setLocationRelativeTo(null);
+
+        JPanel panel = new JPanel(new GridBagLayout());
+        gbc = new GridBagConstraints();
+        gbc.insets = new Insets(5, 5, 5, 5);
+        gbc.fill = GridBagConstraints.HORIZONTAL;
+
+        // Row 0: Name label & field
+        gbc.gridx = 0; gbc.gridy = 0;
+        panel.add(new JLabel("Name:"), gbc);
+        gbc.gridx = 1;
+        txtName = new JTextField(20);
+        panel.add(txtName, gbc);
+
+        // Row 1: Email label & field
+        gbc.gridx = 0; gbc.gridy = 1;
+        panel.add(new JLabel("Email:"), gbc);
+        gbc.gridx = 1;
+        txtEmail = new JTextField(20);
+        panel.add(txtEmail, gbc);
+
+        // Row 2: Password label & field
+        gbc.gridx = 0; gbc.gridy = 2;
+        panel.add(new JLabel("Password:"), gbc);
+        gbc.gridx = 1;
+        txtPassword = new JPasswordField(20);
+        panel.add(txtPassword, gbc);
+
+        // Row 3: Gender selection
+        gbc.gridx = 0; gbc.gridy = 3;
+        panel.add(new JLabel("Gender:"), gbc);
+        gbc.gridx = 1;
+        rbMale = new JRadioButton("Male"); rbFemale = new JRadioButton("Female");
+        ButtonGroup bg = new ButtonGroup(); bg.add(rbMale); bg.add(rbFemale);
+        JPanel genderPanel = new JPanel(); genderPanel.add(rbMale); genderPanel.add(rbFemale);
+        panel.add(genderPanel, gbc);
+
+        // Row 4: Interests selection
+        gbc.gridx = 0; gbc.gridy = 4;
+        panel.add(new JLabel("Interests:"), gbc);
+        gbc.gridx = 1;
+        cbJava = new JCheckBox("Java"); cbPython = new JCheckBox("Python"); cbCpp = new JCheckBox("C++");
+        JPanel interestPanel = new JPanel();
+        interestPanel.add(cbJava); interestPanel.add(cbPython); interestPanel.add(cbCpp);
+        panel.add(interestPanel, gbc);
+
+        // Row 5: Submit button
+        gbc.gridx = 1; gbc.gridy = 5;
+        gbc.anchor = GridBagConstraints.CENTER;
+        btnSubmit = new JButton("Submit");
+        btnSubmit.addActionListener(this);
+        panel.add(btnSubmit, gbc);
+
+        add(panel);
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        String name = txtName.getText();
+        String email = txtEmail.getText();
+        String gender = rbMale.isSelected() ? "Male" : rbFemale.isSelected() ? "Female" : "Unspecified";
+        String interests = "";
+        if (cbJava.isSelected()) interests += "Java ";
+        if (cbPython.isSelected()) interests += "Python ";
+        if (cbCpp.isSelected()) interests += "C++ ";
+
+        JOptionPane.showMessageDialog(this,
+                "Name: " + name + "\n" +
+                        "Email: " + email + "\n" +
+                        "Gender: " + gender + "\n" +
+                        "Interests: " + interests,
+                "Registration Details", JOptionPane.INFORMATION_MESSAGE);
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> new RegistrationFormApp().setVisible(true));
+    }
+}