先上截圖：



原始碼：

import java.awt.*;
import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.undo.UndoManager;
import java.awt.event.*;
import java.io.*;

/**
 * 
 * @author [email protected]
 * @created 2015年7月6日 上午11:22:24
 */
public class JNotepad extends
 
 JFrame implements ActionListener {

    JMenuBar menubar = new JMenuBar();
    JMenu file = new JMenu("檔案(F)");
    JMenu edit = new JMenu("編輯(E)");
    JMenu format = new JMenu("格式(O)");
    JMenu help = new JMenu("幫助(H)");
    JMenuItem create = new JMenuItem("新建");
    JMenuItem open = new JMenuItem("開啟..."
 
);
    JMenuItem save = new JMenuItem("儲存");
    JMenuItem saveAs = new JMenuItem("另存為...");
    JMenuItem exit = new JMenuItem("退出");
    JMenuItem undo = new JMenuItem("撤銷");
    JMenuItem cut = new JMenuItem("剪下");
    JMenuItem copy = new JMenuItem("複製");
    JMenuItem paste = new JMenuItem("貼上"
 
);
    JMenuItem findRep = new JMenuItem("查詢替換");
    JMenuItem selectAll = new JMenuItem("全選");
    JMenuItem font = new JMenuItem("字型");
    JMenuItem about = new JMenuItem("關於");
    JMenuItem cut2 = new JMenuItem("剪下(X)");

    JMenuItem copy2 = new JMenuItem("複製(C)");
    JMenuItem paste2 = new JMenuItem("貼上(V)");
    JMenuItem selectAll2 = new JMenuItem("全選(A)");
    public static JTextArea textarea = new JTextArea();
    UndoManager um = new UndoManager();
    JScrollPane scroll = new JScrollPane(textarea, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
    JPopupMenu popup = new JPopupMenu();
    String pathSelect;

    // 獲取螢幕尺寸
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

    public JNotepad() {

        // 此處定義鍵盤快捷鍵
        // MenuBar
        file.setMnemonic(KeyEvent.VK_F);
        edit.setMnemonic(KeyEvent.VK_E);
        format.setMnemonic(KeyEvent.VK_O);
        help.setMnemonic(KeyEvent.VK_H);
        // MenuItem
        create.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N, ActionEvent.CTRL_MASK));
        open.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, ActionEvent.CTRL_MASK));
        save.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, ActionEvent.CTRL_MASK));
        undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z, ActionEvent.CTRL_MASK));
        cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X, ActionEvent.CTRL_MASK));
        copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C, ActionEvent.CTRL_MASK));
        paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V, ActionEvent.CTRL_MASK));
        findRep.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F, ActionEvent.CTRL_MASK));
        selectAll.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A, ActionEvent.CTRL_MASK));

        // 事件監聽者
        save.addActionListener(this);
        create.addActionListener(this);
        open.addActionListener(this);
        saveAs.addActionListener(this);
        exit.addActionListener(this);
        undo.addActionListener(this);
        cut.addActionListener(this);
        copy.addActionListener(this);
        paste.addActionListener(this);
        selectAll.addActionListener(this);
        font.addActionListener(this);
        about.addActionListener(this);
        cut2.addActionListener(this);
        copy2.addActionListener(this);
        paste2.addActionListener(this);
        selectAll2.addActionListener(this);
        findRep.addActionListener(this);
        // 設定撤銷文字的管理器
        textarea.getDocument().addUndoableEditListener(um);
        textarea.setFont(Format.font);
        // 檔案
        file.add(create);
        file.add(open);
        file.add(save);
        file.add(saveAs);
        file.addSeparator();
        file.add(exit);

        // 編輯
        edit.add(undo);
        edit.addSeparator();
        edit.add(cut);
        edit.add(copy);
        edit.add(paste);
        edit.addSeparator();
        edit.add(findRep);
        edit.addSeparator();
        edit.add(selectAll);

        // 格式
        format.add(font);

        // 幫助
        help.add(about);

        // 選單欄
        menubar.add(file);
        menubar.add(edit);
        menubar.add(format);
        menubar.add(help);

        // 右鍵選單
        popup.add(cut2);
        popup.add(copy2);
        popup.add(paste2);
        popup.addSeparator();
        popup.add(selectAll2);

        // 新增到文字域容器
        textarea.add(popup);

        // 匿名內部類監聽器右鍵動作
        textarea.addMouseListener(new MouseAdapter() {
            public void mouseReleased(MouseEvent e) {
                if (e.getButton() == MouseEvent.BUTTON3) {
                    popup.show(textarea, e.getX(), e.getY());
                }
            }
        });

        // 邊界佈局
        this.add(menubar, BorderLayout.NORTH);
        this.add(scroll, BorderLayout.CENTER);
        this.setTitle("記事本");
        this.setSize(500, 400);
        this.setLocationRelativeTo(null);
        this.setIconImage(new ImageIcon(this.getClass().getResource("/icon/notepad.png")).getImage());//圖示放在源目錄的icon資料夾
        this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        this.setVisible(true);

    }

    // 重寫actionPerformed
    @Override
    public void actionPerformed(ActionEvent e) {
        // Event物件發生源
        if (e.getSource() == open) {

            JFileChooser chooser = new JFileChooser();
            FileNameExtensionFilter filter = new FileNameExtensionFilter("文字文件(*.txt)", "txt");
            chooser.setFileFilter(filter);
            chooser.setDialogTitle("檔案開啟");
            chooser.showOpenDialog(null);
            chooser.setVisible(true);

            try {
                pathSelect = chooser.getSelectedFile().getPath();
                FileReader wjl = new FileReader(pathSelect);
                BufferedReader hcl = new BufferedReader(wjl);
                String s = "", zfc = "";
                while ((s = hcl.readLine()) != null) {
                    zfc += (s + "\n");
                }
                textarea.setText(zfc);

            } catch (Exception e1) {
            }
        }

        if (e.getSource() == saveAs) {// 另存為

            JFileChooser chooser = new JFileChooser();
            FileNameExtensionFilter filter = new FileNameExtensionFilter("文字文件(*.txt)", "txt");
            chooser.setFileFilter(filter);
            chooser.setDialogTitle("另存為");
            chooser.showSaveDialog(null);
            chooser.setVisible(true);

            PrintStream ps;
            try {
                String select = chooser.getSelectedFile().getPath();
                ps = new PrintStream(select);
                System.setOut(ps);
                System.out.println(this.textarea.getText());

            } catch (Exception e1) {
            }
        }

        if (e.getSource() == save && (pathSelect == null)) {// 儲存
            JFileChooser chooser = new JFileChooser();

            chooser.setDialogTitle("儲存");
            chooser.showSaveDialog(null);
            chooser.setVisible(true);

            PrintStream ps;
            try {
                pathSelect = chooser.getSelectedFile().getPath();
                ps = new PrintStream(pathSelect);
                System.setOut(ps);
                System.out.println(this.textarea.getText());

            } catch (Exception e1) {
            }
        } else if (e.getSource() == save && !(pathSelect == null)) {
            PrintStream ps;
            try {
                ps = new PrintStream(pathSelect);
                System.setOut(ps);
                System.out.println(this.textarea.getText());
            } catch (FileNotFoundException e1) {
            }
        }

        if (e.getSource() == create) {
            textarea.setText("");
            pathSelect = null;
        }

        if (e.getSource() == exit) {
            System.exit(0);
        }

        if (e.getSource() == undo) {
            if (um.canUndo()) {
                um.undo();
            }
        }

        if (e.getSource() == cut || e.getSource() == cut2) {
            textarea.cut();
        } else if (e.getSource() == copy || e.getSource() == copy2) {
            textarea.copy();
        } else if (e.getSource() == paste || e.getSource() == paste2) {
            textarea.paste();
        } else if (e.getSource() == findRep) {
            new FindAndReplace(textarea);
        }

        else if (e.getSource() == selectAll || e.getSource() == selectAll2) {
            textarea.selectAll();
        }
        if (e.getSource() == font) {
            new Format(textarea);
        }
        if (e.getSource() == about) {
            new About();
        }

    }

    public static void main(String[] args) {
        new JNotepad();
    }

}

class FindAndReplace extends JDialog implements ActionListener {// 查詢和替換
    JLabel findLabel = new JLabel("查詢內容：");
    JLabel repLabel = new JLabel("    替換為：");
    JTextField findTf = new JTextField(8);
    JTextField repTf = new JTextField(8);
    JButton findBtn = new JButton("查詢");
    JButton repBtn = new JButton("替換");
    JPanel findPn = new JPanel();
    JPanel repPn = new JPanel();
    JTextArea textarea;

    String text;
    boolean flg = false;
    int len;
    int start = 0;
    int k = 0;

    public FindAndReplace(JTextArea textarea) {

        this.textarea = textarea;

        findPn.add(findLabel);
        findPn.add(findTf);
        findPn.add(findBtn);
        repPn.add(repLabel);
        repPn.add(repTf);
        repPn.add(repBtn);
        this.add(findPn);
        this.add(repPn);

        findBtn.addActionListener(this);
        repBtn.addActionListener(this);

        this.setTitle("查詢和替換");
        this.setLayout(new GridLayout(2, 1));
        // this.setBounds(400, 200, 300, 140);
        this.pack();
        this.setLocationRelativeTo(null);
        this.setResizable(false);
        this.setVisible(true);
        this.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
    }

    @SuppressWarnings("deprecation")
    public void actionPerformed(ActionEvent e) {
        String findText = findTf.getText();
        String repText = repTf.getText();
        text = textarea.getText();
        if (e.getSource() == findBtn) {
            findBtn.setLabel("下一個");
            if (findText != null) {
                len = findText.length();
                start = text.indexOf(findText, k);
                k = start + len;
                textarea.select(start, start + len);
                flg = true;
                if (start == -1) {
                    JOptionPane.showMessageDialog(null, "已到檔案尾部！", "提示", JOptionPane.INFORMATION_MESSAGE);
                    start = 0;
                    k = 0;
                    flg = false;
                }
            }
        } else if (e.getSource() == repBtn) {
            if (flg) {
                textarea.replaceRange(repText, start, start + len);
                flg = false;
            }
        }
    }
}

// 字型格式
class Format extends JDialog implements ActionListener {

    public static int style = 0; // 全域性變數型別，預設值為0
    public static int size = 16; // 全域性變數字型大小，預設值為16
    public static Font font = new Font("新宋體", style, size); // 全域性變數字型，預設值為新宋體

    JPanel pn = new JPanel();
    JPanel okCelPn = new JPanel();
    JPanel fontPn = new JPanel();
    JPanel ptPn = new JPanel();
    JLabel fontLabel = new JLabel("字型:   ");
    JLabel fontStyleLabel = new JLabel("    字形:   ");
    JLabel ptLabel = new JLabel("       磅值:   ");
    JButton ok = new JButton("確定");
    JButton cancel = new JButton("取消");
    GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();// 獲取系統中可用的字型的名字
    String[] fontName = e.getAvailableFontFamilyNames();// 獲取系統中可用的字型的名字
    String[] fontType = { "常規", "傾斜", "粗體", "粗偏斜體" };
    JList fontList = new JList(fontName);
    JList fontTypeList = new JList(fontType);
    JScrollPane fontScroll = new JScrollPane(fontList);
    JScrollPane fontTypeScroll = new JScrollPane(fontTypeList);

    JTextArea textarea;
    SpinnerModel spinnerModel = new SpinnerNumberModel(size, // initial value
            0, // min
            100, // max
            2 // Step
    );
    JSpinner spinner = new JSpinner(spinnerModel);

    public Format(JTextArea textarea) {
        this.textarea = textarea;
        ok.addActionListener(this);
        cancel.addActionListener(this);

        pn.setLayout(new GridLayout(2, 1));
        pn.add(fontPn);
        pn.add(ptPn);

        fontPn.add(fontLabel);
        fontPn.add(fontScroll);
        fontPn.add(fontStyleLabel);
        fontPn.add(fontTypeScroll);

        ptPn.add(ptLabel);
        ptPn.add(spinner);

        fontList.setVisibleRowCount(5);
        fontList.setFixedCellWidth(60);
        fontList.setSelectedIndex(50);
        fontList.setSelectedValue(font.getFontName(), true);

        fontTypeList.setVisibleRowCount(5);
        fontTypeList.setSelectedIndex(style);
        okCelPn.add(ok);
        okCelPn.add(cancel);

        okCelPn.setLayout(new FlowLayout(FlowLayout.RIGHT));

        this.add(pn, BorderLayout.CENTER);
        this.add(okCelPn, BorderLayout.SOUTH);

        this.setTitle("字型");
        this.pack();
        this.setLocationRelativeTo(null);
        this.setResizable(false);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == ok) {
            System.out.println(fontList.getSelectedValue());
            style = this.type();
            size = Integer.parseInt(spinner.getValue().toString());
            font = new Font((String) fontList.getSelectedValue(), style, size);
            textarea.setFont(font);
            this.dispose();
            System.out.println(type());
        } else if (e.getSource() == cancel) {
            this.dispose();
        }
    }

    private int type() {
        if (fontTypeList.getSelectedValue().equals("傾斜")) {
            return 1;
        } else if (fontTypeList.getSelectedValue().equals("粗體")) {
            return 2;
        } else if (fontTypeList.getSelectedValue().equals("粗偏斜體")) {
            return 3;
        } else
            return 0;
    }

}

class About extends JDialog {// 關於視窗

    About() {
        JOptionPane.showMessageDialog(null, "            作者：cjb          版本：v1.5\n\n            聯絡：[email protected]", "關於",
                JOptionPane.PLAIN_MESSAGE);
    }
}

轉載請註明出處。