JAVA MVC 2

 

BookController.java

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package bookdb;

import javax.swing.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

public class BookController {

    private final BookModel model;

    private final BookView view;

    public BookController(BookModel model, BookView view) {

        this.model = model;

        this.view = view;

        // Tell the view to forward "Add" button clicks here

        this.view.addRegisterListener(new AddBookListener());

    }

    // Inner class to handle button clicks

    private class AddBookListener implements ActionListener {

        @Override

        public void actionPerformed(ActionEvent e) {

            String title = view.getBookTitle();

            String author = view.getBookAuthor();

            // Simple validation

            if (title.isEmpty() || author.isEmpty()) {

                JOptionPane.showMessageDialog(view, 

                        "Both Title and Author are required!", 

                        "Error", JOptionPane.ERROR_MESSAGE);

                return;

            }

            // Update Model (which automatically updates JTable via firing events)

            model.addBook(title, author);

            

            // Clear View UI inputs

            view.clearInputs();

        }

    }

}

========================================

BookModel.java

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package bookdb;

import javax.swing.table.AbstractTableModel;

import java.util.ArrayList;

import java.util.List;

// Simple Data Object

class Book {

    private String title;

    private String author;

    public Book(String title, String author) {

        this.title = title;

        this.author = author;

    }

    public String getTitle() { return title; }

    public String getAuthor() { return author; }

}

// The Table Model that JTable communicates with

public class BookModel extends AbstractTableModel {

    private final List<Book> books = new ArrayList<>();

    private final String[] columnNames = {"Title", "Author"};

    public BookModel() {

        // Sample Data

        books.add(new Book("The Hobbit", "J.R.R. Tolkien"));

        books.add(new Book("184", "George Orwell"));

    }

    public void addBook(String title, String author) {

        books.add(new Book(title, author));

        // Notify the JTable that data has changed so it refreshes UI

        fireTableDataChanged();

    }

    @Override

    public int getRowCount() { return books.size(); }

    @Override

    public int getColumnCount() { return columnNames.length; }

    @Override

    public String getColumnName(int column) { return columnNames[column]; }

    @Override

    public Object getValueAt(int rowIndex, int columnIndex) {

        Book book = books.get(rowIndex);

        if (columnIndex == 0) return book.getTitle();

        if (columnIndex == 1) return book.getAuthor();

        return null;

    }

}

========================================

BookView.java

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package bookdb;

import javax.swing.*;

import java.awt.*;

import java.awt.event.ActionListener;

public class BookView extends JFrame {

    private final JTable table;

    private final JTextField titleField = new JTextField(15);

    private final JTextField authorField = new JTextField(15);

    private final JButton addButton = new JButton("Add Book");

    public BookView(BookModel model) {

        setTitle("Book Database (MVC)");

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        setSize(500, 400);

        setLocationRelativeTo(null);

        // Table setup

        table = new JTable(model);

        JScrollPane scrollPane = new JScrollPane(table);

        // Input Panel setup

        JPanel inputPanel = new JPanel(new GridBagLayout());

        GridBagConstraints gbc = new GridBagConstraints();

        gbc.insets = new Insets(5, 5, 5, 5);

        gbc.gridx = 0; gbc.gridy = 0;

        inputPanel.add(new JLabel("Title:"), gbc);

        gbc.gridx = 1;

        inputPanel.add(titleField, gbc);

        gbc.gridx = 0; gbc.gridy = 1;

        inputPanel.add(new JLabel("Author:"), gbc);

        gbc.gridx = 1;

        inputPanel.add(authorField, gbc);

        gbc.gridx = 1; gbc.gridy = 2;

        inputPanel.add(addButton, gbc);

        // Layout integration

        setLayout(new BorderLayout());

        add(scrollPane, BorderLayout.CENTER);

        add(inputPanel, BorderLayout.SOUTH);

    }

    // Getters for Controller to fetch input data

    public String getBookTitle() { return titleField.getText().trim(); }

    public String getBookAuthor() { return authorField.getText().trim(); }

    public void clearInputs() {

        titleField.setText("");

        authorField.setText("");

    }

    // Wire up the button to the Controller listener

    public void addRegisterListener(ActionListener listener) {

        addButton.addActionListener(listener);

    }

}

========================================================

Main.java

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package bookdb;

import javax.swing.*;

public class Main {

    public static void main(String[] args) {

        // Run UI initialization on the Event Dispatch Thread for thread safety

        SwingUtilities.invokeLater(() -> {

            // 1. Instantiate Model

            BookModel model = new BookModel();

            // 2. Instantiate View and pass Model to the JTable

            BookView view = new BookView(model);

            // 3. Instantiate Controller to link them together

            new BookController(model, view);

            // 4. Show the UI

            view.setVisible(true);

        });

    }

}