记事本

 package a1;

import java.awt.Color;  
import java.awt.Dimension;  
import java.awt.EventQueue;  
import java.awt.Font;  
import java.awt.GraphicsEnvironment;  
import java.awt.Insets;  
import java.awt.Toolkit;  
import java.awt.event.ActionEvent;  
import java.awt.event.ActionListener;  
import java.io.File;  
import java.io.FileReader;  
import java.io.FileWriter;  
import java.io.IOException;  
  
import javax.swing.JCheckBoxMenuItem;  
import javax.swing.JColorChooser;  
import javax.swing.JFileChooser;  
import javax.swing.JFrame;  
import javax.swing.JList;  
import javax.swing.JMenu;  
import javax.swing.JMenuBar;  
import javax.swing.JMenuItem;  
import javax.swing.JOptionPane;  
import javax.swing.JScrollPane;  
import javax.swing.JTextArea;  
import javax.swing.UIManager;  
import javax.swing.UnsupportedLookAndFeelException;  
import javax.swing.undo.UndoManager;  
/** 
 * swing 简单记事本 
 * @author kissy小强 
 * 
 */  
public class Note extends JFrame {  
    private static final long serialVersionUID = 1L;  
    UndoManager manager = new UndoManager();  
    JTextArea text = new JTextArea();  
    JFileChooser chooser;  
    String s = "新建记事本";  
    int result = 0;  
    private File file;  
    JMenuBar Mb;  
    JMenu M1, M2, M3, M4;  
    JMenuItem m11, m12, m13, m14, m15, m21, m22, m23, m24, m25, m32, m33, m41;  
    private final static int HEIGHT=450;    
    private final static int WIDTH=750;    
    JCheckBoxMenuItem m31 = new JCheckBoxMenuItem("自动换行", true);  
  
    public static void main(String args[]) {  
        String lookAndFeel = UIManager.getSystemLookAndFeelClassName();  
        try {  
            UIManager.setLookAndFeel(lookAndFeel);  
        } catch (ClassNotFoundException | InstantiationException  
                | IllegalAccessException | UnsupportedLookAndFeelException e1) {  
            e1.printStackTrace();  
        }  
        EventQueue.invokeLater(new Runnable() {  
            public void run() {  
                try {  
                    Note n = new Note();  
                } catch (Exception e) {  
                    e.printStackTrace();  
                }  
            }  
        });  
    }  
      
    public Note() {  
        setTitle(s);  
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);  
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();  
        // 离显示屏上边缘x像素，里显示屏左边缘y像素  
        setLocation(screenSize.width / 2 - WIDTH / 2, screenSize.height / 2- HEIGHT / 2);  
        setSize(WIDTH, HEIGHT);  
        setResizable(true); // 窗体是否可变  
        setVisible(true); // 窗体是否可见  
        init();  
    }  
      
    private void init(){  
        Mb = new JMenuBar();  
        this.setJMenuBar(Mb);  
        text.getDocument().addUndoableEditListener(manager);// 设置文本框编辑监听（可撤销）  
        text.setFont(new Font("宋体", Font.PLAIN, 14));  
        text.setCaretColor(Color.RED);// 光标颜色  
        text.setSelectedTextColor(Color.RED);// 选中字体颜色  
        text.setSelectionColor(Color.GREEN);// 选中背景颜色  
        text.setLineWrap(true); // 是否换行  
        text.setWrapStyleWord(true); // 是否单词边界换行（即有空白）  
        text.setMargin(new Insets(3, 5, 3, 5));// 文本区与边框的间距，四个参数分别为上、左、下、右  
        text.setDragEnabled(true); // 开启或关闭自动拖动处理  
        add(new JScrollPane(text, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,  
                JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));  
  
        M1 = this.AddBar("文件", Mb);  
        M2 = this.AddBar("编辑", Mb);  
        M3 = this.AddBar("格式", Mb);  
        M4 = this.AddBar("帮助", Mb);  
        /* 新建选项 */  
        m11 = this.AddItem("新建", M1);  
        m11.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                text.setText("");  
                setTitle(s);  
                file = null;  
            }  
        });  
        /* 打开选项 */  
        m12 = this.AddItem("打开", M1);  
        m12.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                try {  
                    // 设置打开时的默认目录，两种方式  
                    chooser = new JFileChooser("C:\\Users\\xiaozhx\\Desktop");  
                    // chooser.setCurrentDirectory(new File("C:\\Users\\xiaozhx\\Desktop"));  
                    chooser.setFileFilter(new filter());  
                    result = chooser.showOpenDialog(null);  
                    if (result == JFileChooser.APPROVE_OPTION) {  
                        // 点击了打开按钮  
                        file = chooser.getSelectedFile();  
                        int length = (int) file.length();  
                        FileReader reader = new FileReader(file);  
                        char[] ch = new char[length];  
                        reader.read(ch);  
                        reader.close();  
                        text.setText(new String(ch).trim());  
                        setTitle(file.getName());  
                    } else if (result == JFileChooser.CANCEL_OPTION) {  
                        // 点击了取消按钮  
                    }  
                } catch (Exception e) {  
                    JOptionPane.showMessageDialog(null, e);  
                }  
            }  
        });  
        /* 保存选项 */  
        m13 = this.AddItem("保存", M1);  
        m13.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                if (file == null)  
                    try {  
                        chooser = new JFileChooser("G:\\java大作战\test1");  
                        chooser.setFileFilter(new filter());  
                        result = chooser.showSaveDialog(null);  
                        if (result == JFileChooser.APPROVE_OPTION) {  
                            File selectfile = chooser.getSelectedFile(); // 获得文件名  
                            // 获得被选中的过滤器中的文件扩展名  
                            String end = chooser.getFileFilter().getDescription();  
                            File newFile = null;  
                            if (selectfile.getAbsolutePath().toUpperCase().endsWith(end.toUpperCase())) {  
                                // 如果文件是以选定扩展名结束的，则使用原名  
                                newFile = selectfile;  
                            } else {  
                                // 否则加上选定的扩展名  
                                newFile = new File(selectfile.getAbsolutePath()+ end);  
                            }  
                            try {  
                                if (newFile.exists() == false) {  
                                    newFile.createNewFile();  
                                }  
                                FileWriter writer = new FileWriter(newFile);  
                                char[] arry = text.getText().toCharArray();  
                                writer.write(arry);  
                                writer.flush();  
                                writer.close();  
                                setTitle(newFile.getName());  
                                file = newFile;  
                            } catch (IOException e) {  
                            }  
                        } else if (result == JFileChooser.CANCEL_OPTION) {  
                            // 点击了取消按钮  
                        }  
                    } catch (Exception e) {  
                        JOptionPane.showMessageDialog(null, e);  
                    }  
                else  
                    try {  
                        FileWriter writer = new FileWriter(file);  
                        char[] arry = text.getText().toCharArray();  
                        writer.write(arry);  
                        writer.flush();  
                        writer.close();  
                    } catch (Exception e) {  
                        JOptionPane.showMessageDialog(null, e);  
                    }  
            }  
        });  
        /* 另存为选项 */  
        m14 = this.AddItem("另存为", M1);  
        m14.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                try {  
                    chooser = new JFileChooser("C:\\Users\\xiaozhx\\Desktop");  
                    chooser.setFileFilter(new filter());  
                    result = chooser.showSaveDialog(null);  
                    if (result == JFileChooser.APPROVE_OPTION) {  
                        File selectfile = chooser.getSelectedFile(); // 获得文件名  
                        // 获得被选中的过滤器中的文件扩展名  
                        String end = chooser.getFileFilter().getDescription();  
                        File newFile = null;  
                        if (selectfile.getAbsolutePath().toUpperCase().endsWith(end.toUpperCase())) {  
                            // 如果文件是以选定扩展名结束的，则使用原名  
                            newFile = selectfile;  
                        } else {  
                            // 否则加上选定的扩展名  
                            newFile = new File(selectfile.getAbsolutePath()+ end);  
                        }  
                        try {  
                            if (newFile.exists() == false) {  
                                newFile.createNewFile();  
                            }  
                            FileWriter writer = new FileWriter(newFile);  
                            char[] arry = text.getText().toCharArray();  
                            writer.write(arry);  
                            writer.flush();  
                            writer.close();  
                            setTitle(newFile.getName());  
                            file = newFile;  
                        } catch (IOException e) {  
                        }  
                    } else if (result == JFileChooser.CANCEL_OPTION) {  
                        // 点击了取消按钮  
                    }  
                } catch (Exception e) {  
                    JOptionPane.showMessageDialog(null, e);  
                }  
            }  
        });  
  
        M1.addSeparator(); // 横杆  
        /* 退出选项 */  
        m15 = this.AddItem("退出", M1);  
        m15.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                System.exit(0);  
            }  
        });  
        /* 撤消选项 */  
        m21 = this.AddItem("撤消", M2);  
        m21.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                if (manager.canUndo())  
                    manager.undo();  
            }  
        });  
        /* 剪切选项 */  
        M2.addSeparator();  
        m22 = this.AddItem("剪切", M2);  
        m22.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                text.cut();  
            }  
        });  
        /* 复制选项 */  
        m23 = this.AddItem("复制", M2);  
        m23.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                text.copy();  
            }  
        });  
        /* 粘贴选项 */  
        m24 = this.AddItem("粘贴", M2);  
        m24.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                text.paste();  
            }  
        });  
        /* 删除选项 */  
        m25 = this.AddItem("删除", M2);  
        m25.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                text.replaceRange("", text.getSelectionStart(),  
                        text.getSelectionEnd());  
            }  
        });  
        /* 自动换行选项 */  
        M3.add(m31);  
        m31.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                if (m31.getState())  
                    text.setLineWrap(true);  
                else  
                    text.setLineWrap(false);  
            }  
        });  
        /* 字体格式设置选项 */  
        m32 = this.AddItem("字体选择", M3);  
        m32.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                GraphicsEnvironment ge = GraphicsEnvironment  
                        .getLocalGraphicsEnvironment();  
                //获取系统字体  
                JList<String> fontNames = new JList<String>(ge.getAvailableFontFamilyNames());  
                int response = JOptionPane.showConfirmDialog(null,  
                        new JScrollPane(fontNames), "请选择字体",  
                        JOptionPane.OK_CANCEL_OPTION);  
                Object selectedFont = fontNames.getSelectedValue();  
                if (response == JOptionPane.OK_OPTION && selectedFont != null)  
                    text.setFont(new Font(fontNames.getSelectedValue()  
                            .toString(), Font.PLAIN, 20));  
            }  
        });  
        /* 字体颜色设置选项 */  
        m33 = this.AddItem("字体颜色", M3);  
        m33.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                Color color = JColorChooser.showDialog(null, "文字颜色选择",  
                        Color.WHITE);  
                text.setForeground(color);  
            }  
        });  
  
        m41 = this.AddItem("关于记事本", M4);  
        m41.addActionListener(new ActionListener() {  
            public void actionPerformed(ActionEvent event) {  
                JOptionPane.showMessageDialog(null, "java记事本",  
                        "关于", JOptionPane.PLAIN_MESSAGE);  
            }  
        });  
    }  
    /** 文件格式过滤器 **/  
    private class filter extends javax.swing.filechooser.FileFilter {  
        public boolean accept(File file) {  
            String name = file.getName();  
            name.toLowerCase();  
            if (name.endsWith(".txt") || file.isDirectory())  
                return true;  
            else  
                return false;  
        }  
  
        public String getDescription() {  
            return ".txt";  
        }  
    }  
  
    /** 将菜单项JMenuItem添加到菜单JMenu **/  
    public JMenuItem AddItem(String name, JMenu menu) {  
        JMenuItem MI = new JMenuItem(name);  
        menu.add(MI);  
        return MI;  
    }  
  
    /** 将菜单JMenu添加到菜栏JMenuBar **/  
    public JMenu AddBar(String name, JMenuBar mb) {  
        JMenu Mb = new JMenu(name);  
        mb.add(Mb);  
        return Mb;  
    }  
  
}