Java Source - Simple Editor.

This very simple editor illustrates several things: the use of menus, JFileChooser, and Actions.
Ví dụ đơn giản này minh họa một vài điều về việc sử dụng các menus, JFileChooser, và các action.




NutPad.Java

// File   : editor/NutPad.java -- A very simple text editor
// Purpose: Illustrates use of AbstractActions for menus.
//          It only uses a few Action features.  Many more are available.
//          This program uses the obscure "read" and "write"
//               text component methods.
// Author : Fred Swartz - 2006-12-14 - Placed in public domain.

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

/////////// NutPad
public class NutPad extends JFrame {
    //... Components
    private JTextArea    _editArea;
    private JFileChooser _fileChooser = new JFileChooser();
   
    //... Create actions for menu items, buttons, ...
    private Action _openAction = new OpenAction();
    private Action _saveAction = new SaveAction();
    private Action _exitAction = new ExitAction();
   
    //=== main
    public static void main(String[] args) {
        new NutPad();
    }
   
    //======= constructor
    public NutPad() {
        //... Create scrollable text area.
        _editArea = new JTextArea(15, 80);
        _editArea.setBorder(BorderFactory.createEmptyBorder(2,2,2,2));
        _editArea.setFont(new Font("monospaced", Font.PLAIN, 14));
        JScrollPane scrollingText = new JScrollPane(_editArea);
       
        //-- Create a content pane, set layout, add component.
        JPanel content = new JPanel();
        content.setLayout(new BorderLayout());
        content.add(scrollingText, BorderLayout.CENTER);
       
        //... Create menubar
        JMenuBar menuBar = new JMenuBar();
        JMenu fileMenu = menuBar.add(new JMenu("File"));
        fileMenu.setMnemonic('F');
        fileMenu.add(_openAction);       // Note use of actions, not text.
        fileMenu.add(_saveAction);
        fileMenu.addSeparator();
        fileMenu.add(_exitAction);
       
        //... Set window content and menu.
        setContentPane(content);
        setJMenuBar(menuBar);
       
        //... Set other window characteristics.
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("NutPad");
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }
   
    ////////////////////////////////////////////////// inner class OpenAction
    class OpenAction extends AbstractAction {
        //=========== constructor
        public OpenAction() {
            super("Open...");
            putValue(MNEMONIC_KEY, new Integer('O'));
        }
       
        //======= actionPerformed
        public void actionPerformed(ActionEvent e) {
            int retval = _fileChooser.showOpenDialog(NutPad.this);
            if (retval == JFileChooser.APPROVE_OPTION) {
                File f = _fileChooser.getSelectedFile();
                try {
                    FileReader reader = new FileReader(f);
                    _editArea.read(reader, "");  // Use TextComponent read
                } catch (IOException ioex) {
                    System.out.println(e);
                    System.exit(1);
                }
            }
        }
    }
   
    //////////////////////////////////////////////////// inner class SaveAction
    class SaveAction extends AbstractAction {
        //=========== constructor
        SaveAction() {
            super("Save...");
            putValue(MNEMONIC_KEY, new Integer('S'));
        }
       
        //======= actionPerformed
        public void actionPerformed(ActionEvent e) {
            int retval = _fileChooser.showSaveDialog(NutPad.this);
            if (retval == JFileChooser.APPROVE_OPTION) {
                File f = _fileChooser.getSelectedFile();
                try {
                    FileWriter writer = new FileWriter(f);
                    _editArea.write(writer);  // Use TextComponent write
                } catch (IOException ioex) {
                    JOptionPane.showMessageDialog(NutPad.this, ioex);
                    System.exit(1);
                }
            }
        }
    }
   
    ///////////////////////////////////////////////////// inner class ExitAction
    class ExitAction extends AbstractAction {
       
        //=========== constructor
        public ExitAction() {
            super("Exit");
            putValue(MNEMONIC_KEY, new Integer('X'));
        }
       
        //======= actionPerformed
        public void actionPerformed(ActionEvent e) {
            System.exit(0);
        }
    }
}

Kết quả - Result