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();
   }
  }
 }

}