Java メモ帳

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class SimpleNotepad extends JFrame implements ActionListener {
    private JTextArea textArea;
    private JMenuItem openItem, saveItem, exitItem;

    public SimpleNotepad() {
        // Frame settings
        setTitle("Simple Notepad");
        setSize(800, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Text area settings
        textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);
        add(scrollPane, BorderLayout.CENTER);

        // Menu bar creation
        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        openItem = new JMenuItem("Open");
        saveItem = new JMenuItem("Save");
        exitItem = new JMenuItem("Exit");

        openItem.addActionListener(this);
        saveItem.addActionListener(this);
        exitItem.addActionListener(this);

        fileMenu.add(openItem);
        fileMenu.add(saveItem);
        fileMenu.add(exitItem);
        menuBar.add(fileMenu);
        setJMenuBar(menuBar);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == openItem) {
            openFile();
        } else if (e.getSource() == saveItem) {
            saveFile();
        } else if (e.getSource() == exitItem) {
            System.exit(0);
        }
    }

    private void openFile() {
        JFileChooser fileChooser = new JFileChooser();
        int option = fileChooser.showOpenDialog(this);
        if (option == JFileChooser.APPROVE_OPTION) {
            try (BufferedReader reader = new BufferedReader(new FileReader(fileChooser.getSelectedFile()))) {
                textArea.read(reader, null);
            } catch (IOException ex) {
                JOptionPane.showMessageDialog(this, "File could not be opened", "Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    private void saveFile() {
        JFileChooser fileChooser = new JFileChooser();
        int option = fileChooser.showSaveDialog(this);
        if (option == JFileChooser.APPROVE_OPTION) {
            try (FileWriter writer = new FileWriter(fileChooser.getSelectedFile())) {
                textArea.write(writer);
            } catch (IOException ex) {
                JOptionPane.showMessageDialog(this, "File could not be saved", "Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            SimpleNotepad notepad = new SimpleNotepad();
            notepad.setVisible(true);
        });
    }
}

投稿者: chosuke

趣味はゲームやアニメや漫画などです chosuke のすべての投稿を表示