javalab/P10.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;

public class P10 extends JFrame {
    private JTextArea textArea;
    private JFileChooser fileChooser;

    public P10() {
        setTitle("Swing Text Editor");
        setSize(800, 600);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        textArea = new JTextArea();
        JScrollPane scrollPane = new JScrollPane(textArea);
        add(scrollPane, BorderLayout.CENTER);

        fileChooser = new JFileChooser();

        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = new JMenu("File");
        JMenuItem openMenuItem = new JMenuItem("Open");
        JMenuItem saveMenuItem = new JMenuItem("Save");
        JMenuItem exitMenuItem = new JMenuItem("Exit");

        openMenuItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int returnVal = fileChooser.showOpenDialog(P10.this);
                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    File file = fileChooser.getSelectedFile();
                    try {
                        BufferedReader reader = new BufferedReader(new FileReader(file));
                        textArea.read(reader, null);
                        reader.close();
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        saveMenuItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int returnVal = fileChooser.showSaveDialog(P10.this);
                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    File file = fileChooser.getSelectedFile();
                    try {
                        BufferedWriter writer = new BufferedWriter(new FileWriter(file));
                        textArea.write(writer);
                        writer.close();
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        });

        exitMenuItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });

        fileMenu.add(openMenuItem);
        fileMenu.add(saveMenuItem);
        fileMenu.add(exitMenuItem);
        menuBar.add(fileMenu);
        setJMenuBar(menuBar);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                P10 editor = new P10();
                editor.setVisible(true);
            }
        });
    }
}