Java 实现记事本

用java写了一个类似于winddows的记事本，主要实现新建，打开，保存，另存为，关闭，退出等功能，

这是源代码：

/**

 * @time 2011-10-11 下午05:03:27

 * @author Rookie

 * @version 1.0

 * @function 记事本：实现新建，打开，保存，另存为，关闭，退出等功能

 *

 */

import java.awt.BorderLayout;

import java.awt.FileDialog;

import java.awt.Menu;

import java.awt.MenuBar;

import java.awt.MenuItem;

import java.awt.MenuShortcut;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.BufferedInputStream;

import java.io.BufferedWriter;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import javax.swing.JFrame;

import javax.swing.JScrollPane;

import javax.swing.JTextArea;

import javax.swing.text.JTextComponent;

public class MyNotepad

{

 static JFrame frame;

 static JScrollPane textScroll = null;

 static JTextArea textArea = null;

 public static final int FRAME_WIDTH = 800;

 public static final int FRAME_HEIGHT = 600;

 public static final void init()

 {

  frame = new JFrame("记事本");

  // ImageIcon image = new ImageIcon("src/myPicture.jpg");

  // frame.setIconImage(image.getImage());

  // 1、菜单条

  MenuBar menuBar = new MenuBar();

  frame.setMenuBar(menuBar);

  // 2、创建菜单

  Menu fileMenu = new Menu("文件(F)");

  Menu editMenu = new Menu("编辑(E)");

  Menu formatMenu = new Menu("格式(O)");

  menuBar.add(fileMenu);

  menuBar.add(editMenu);

  menuBar.add(formatMenu);

  // 3、文件子菜单项

  MenuItem openFile = new MenuItem("打开文件", new MenuShortcut(0x4F, true));

  MenuItem newFile = new MenuItem("新建", new MenuShortcut(0x4E, true));

  MenuItem save = new MenuItem("保存", new MenuShortcut(0x53, false));

  MenuItem saveAs = new MenuItem("另存为", new MenuShortcut(0x53, true));

  MenuItem close = new MenuItem("关闭", new MenuShortcut(0x57, false));

  MenuItem exit = new MenuItem("退出");

  fileMenu.add(newFile);

  fileMenu.add(openFile);

  fileMenu.insertSeparator(2);

  fileMenu.add(close);

  fileMenu.insertSeparator(4);

  fileMenu.add(save);

  fileMenu.add(saveAs);

  fileMenu.add(exit);

  // 创建文本域

  textArea = new JTextArea();

  // 创建滚动条

  textScroll = new JScrollPane(textArea);

  frame.add(textScroll, BorderLayout.CENTER);

  // 1、打开文件处理事件

  openFile.addActionListener(new ActionListener()

  {

   public void actionPerformed(ActionEvent e)

   {

    FileDialog openFileDialog = new FileDialog(frame, "打开",

      FileDialog.LOAD);

    openFileDialog.setVisible(true);

    textArea.setVisible(true);

    // 得到文件名

    String openedFileName = openFileDialog.getFile();

    String openedFileDirectory = openFileDialog.getDirectory();

    String openedFilePath = openedFileDirectory + openedFileName;

    if (openedFileName.equals("") || openedFileName == null)

    {

     frame.setTitle("无标题 - 记事本");

    }

    else

    {

     frame.setTitle(openedFileName + " - 记事本");

    }

    try

    {

     writerBuffertoJTextArea(openedFilePath, textArea);

    }

    catch (IOException e1)

    {

     e1.printStackTrace();

    }

   }

  });

  // 2、 新建事件处理

  newFile.addActionListener(new ActionListener()

  {

   @Override

   public void actionPerformed(ActionEvent e)

   {

    textArea.setVisible(true);

    frame.setTitle("无标题 - 记事本");

    textArea.setText("");

   }

  });

  // 3、 关闭文件事件

  close.addActionListener(new ActionListener()

  {

   public void actionPerformed(ActionEvent e)

   {

    textArea.setVisible(false);

    // textArea = null;

   }

  });

  // 4、保存文件事件

  save.addActionListener(new ActionListener()

  {

   @Override

   public void actionPerformed(ActionEvent e)

   {

    FileDialog saveFileDialog = new FileDialog(frame, "保存",

      FileDialog.SAVE);

    saveFileDialog.setVisible(true);

    // 得到文件名

    String saveFileName = saveFileDialog.getFile();

    String saveFileDirectory = saveFileDialog.getDirectory();

    String saveFilePath = saveFileDirectory + saveFileName;

    if (saveFileName.equals("") || saveFileName == null)

    {

     frame.setTitle("无标题 - 记事本");

    }

    else

    {

     frame.setTitle(saveFileName + " - 记事本");

    }

    try

    {

     textBufferToFile(textArea, saveFilePath);

    }

    catch (IOException e1)

    {

     e1.printStackTrace();

    }

   }

  });

  // 5、另存为事件处理

  saveAs.addActionListener(new ActionListener()

  {

   @Override

   public void actionPerformed(ActionEvent e)

   {

    FileDialog saveAsFileDialog = new FileDialog(frame, "另存为",

      FileDialog.SAVE);

    saveAsFileDialog.setVisible(true);

    // 得到文件名

    String saveAsFileName = saveAsFileDialog.getFile();

    String saveAsFileDirectory = saveAsFileDialog.getDirectory();

    String svaeAsFilePath = saveAsFileDirectory + saveAsFileName;

    if (saveAsFileName.equals("") || saveAsFileName == null)

    {

     frame.setTitle("无标题 - 记事本");

    }

    else

    {

     frame.setTitle(saveAsFileName + " - 记事本");

    }

    try

    {

     textBufferToFile(textArea, svaeAsFilePath);

    }

    catch (IOException e1)

    {

     e1.printStackTrace();

    }

   }

  });

  // 6、退出事件处理

  exit.addActionListener(new ActionListener()

  {

   @Override

   public void actionPerformed(ActionEvent e)

   {

    System.exit(0);

   }

  });

  // 3.2、编辑子菜单项

  MenuItem copy = new MenuItem("复制", new MenuShortcut(0x43, false));

  MenuItem cut = new MenuItem("剪切", new MenuShortcut(0x58, false));

  MenuItem paste = new MenuItem("粘贴", new MenuShortcut(0x56, false));

  MenuItem edition = new MenuItem("版本");

  editMenu.add(copy);

  editMenu.add(cut);

  editMenu.add(paste);

  editMenu.add(edition);

  editMenu.insertSeparator(3);

  // 3.3 格式字菜单项

  MenuItem autoLine = new MenuItem("自动换行");

  MenuItem font = new MenuItem("字体");

  formatMenu.add(autoLine);

  formatMenu.add(font);

  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);

  frame.setLocation(100, 20);

  frame.setVisible(true);

 }

 public static void main(String[] args)

 {

  init();

 }

 // 把一个文件里面的内容写入文本框

 public static final void writerBuffertoJTextArea(String fileFrom,

   JTextComponent text) throws IOException

 {

  InputStream inBuffer = null;

  OutputStream outBuffer = null;

  InputStream in = null;

  OutputStream out = null;

  try

  {

   in = new FileInputStream(fileFrom);

   inBuffer = new BufferedInputStream(in);

   StringBuffer sb = new StringBuffer();

   while (true)

   {

    byte[] b = new byte[1024];

    int bytedata = inBuffer.read(b);

    sb = sb.append(new String(b));

    if (bytedata == -1)

    {

     break;

    }

   }

   text.setText(sb.toString());

  }

  finally

  {

   if (inBuffer != null)

   {

    inBuffer.close();

   }

   if (outBuffer != null)

   {

    outBuffer.close();

   }

  }

 }

 // 把文本框里面的内容写入一个文件中

 // 写文件

 public static final void textBufferToFile(JTextComponent text, String fileTo)

   throws IOException

 {

  FileOutputStream out = null;

  OutputStreamWriter outWriter = null;

  BufferedWriter bufferedWriter = null;

  try

  {

   out = new FileOutputStream(fileTo, false);

   outWriter = new OutputStreamWriter(out);

   bufferedWriter = new BufferedWriter(outWriter);

   String content = new String(text.getText());

   bufferedWriter.write(content);

  }

  finally

  {

   if (bufferedWriter != null)

   {

    bufferedWriter.close();

   }

   if (outWriter != null)

   {

    outWriter.close();

   }

   if (out != null)

   {

    out.close();

   }

  }

 }

}