跪求JAVA程序设计

1,import java.awt.*;
import java.awt.event.*;
import java.awt.print.*;
import java.awt.datatransfer.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;

public class JNotepad extends JPanel
{
JTextArea jta = new JTextArea("", 24, 40);

JScrollPane jsp = new JScrollPane(jta);

JMenuBar jmb = new JMenuBar();
JMenu file = new JMenu("File");
JMenu edit = new JMenu("Edit");
JMenu help = new JMenu("Help");
JMenu search = new JMenu("Search");

JToolBar toolBar = new JToolBar();

JMenuItem jmi;

Clipboard clipbd = getToolkit().getSystemClipboard();

PrinterJob prtMe = PrinterJob.getPrinterJob();

String text = "";

public JNotepad()
{
class newL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.setDocument(new PlainDocument());
}
}

class openL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
JFileChooser fc = new JFileChooser();
int returnVal = fc.showDialog(JNotepad.this, "Open file");
if(returnVal == JFileChooser.APPROVE_OPTION)
{
String file = fc.getSelectedFile().getPath();
if(file == null)
{
return;
}
try
{
Reader in = new FileReader(file);
char[] buff = new char[4096];
int nch;
while((nch = in.read(buff, 0, buff.length)) != -1)
{
jta.setDocument(new PlainDocument());
jta.append(new String(buff, 0, nch));
}
}
catch (IOException io)
{
System.err.println("IOException: " + io.getMessage());
}
}
else
{
return;
}
}
}

class saveL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
JFileChooser fc = new JFileChooser();
int returnVal = fc.showSaveDialog(JNotepad.this);
if(returnVal == JFileChooser.APPROVE_OPTION)
{
String savefile = fc.getSelectedFile().getPath();
if(savefile == null)
{
return;
}
else
{
String docToSave = jta.getText();
if(docToSave != null)
{
FileOutputStream fstrm = null;
BufferedOutputStream ostrm = null;
try
{
fstrm = new FileOutputStream(savefile);
ostrm = new BufferedOutputStream(fstrm);
byte[] bytes = null;
try
{
bytes = docToSave.getBytes();
}
catch(Exception e1)
{
e1.printStackTrace();
}
ostrm.write(bytes);
}
catch(IOException io)
{
System.err.println("IOException: " +
io.getMessage());
}
finally
{
try
{
ostrm.flush();
fstrm.close();
ostrm.close();
}
catch(IOException ioe)
{
System.err.println("IOException: " +
ioe.getMessage());
}
}
}
}
}
else
{
return;
}
}
}

class pageSetupL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
prtMe.printDialog();
}
}

class printL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
try
{
prtMe.print();
}
catch(Exception ew)
{
}
}
}

class exitL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}

class copyL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String selection = jta.getSelectedText();
StringSelection clipString = new StringSelection(selection);
clipbd.setContents(clipString, clipString);
}
}

class cutL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String selection = jta.getSelectedText();
StringSelection clipString = new StringSelection(selection);
clipbd.setContents(clipString, clipString);
jta.replaceRange("", jta.getSelectionStart(),
jta.getSelectionEnd());
}
}

class pasteL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
Transferable clipData = clipbd.getContents(JNotepad.this);
try
{
String clipString =
(String)clipData.getTransferData(
DataFlavor.stringFlavor);
jta.replaceRange(clipString,
jta.getSelectionStart(), jta.getSelectionEnd());
}
catch(Exception ex)
{
}
}
}

class deleteL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String selection = jta.getSelectedText();
jta.replaceRange("", jta.getSelectionStart(),
jta.getSelectionEnd());
}
}

class selectAllL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
jta.selectAll();
}
}

class findL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String find = "";
find = JOptionPane.showInputDialog(
"Find what: ");
}
}

class findNextL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
}
}

class aboutL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
JOptionPane.showMessageDialog(null,
"JNotepad Developed By thyokel");
}
}

class jtaL implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
}
}

file.add(jmi = new JMenuItem("New", KeyEvent.VK_N));
jmi.addActionListener(new newL());
file.add(jmi = new JMenuItem("Open", KeyEvent.VK_O));
jmi.addActionListener(new openL());
file.add(jmi = new JMenuItem("Save", KeyEvent.VK_S));
jmi.addActionListener(new saveL());
file.addSeparator();
file.add(jmi = new JMenuItem("Page Setup", KeyEvent.VK_G));
jmi.addActionListener(new pageSetupL());
file.add(jmi = new JMenuItem("Print", KeyEvent.VK_P));
jmi.addActionListener(new printL());
file.addSeparator();
file.add(jmi = new JMenuItem("Exit", KeyEvent.VK_X));
jmi.addActionListener(new exitL());

edit.add(jmi = new JMenuItem("Copy", KeyEvent.VK_C));
jmi.addActionListener(new copyL());
edit.add(jmi = new JMenuItem("Cut", KeyEvent.VK_T));
jmi.addActionListener(new cutL());
edit.add(jmi = new JMenuItem("Paste", KeyEvent.VK_P));
jmi.addActionListener(new pasteL());
edit.add(jmi = new JMenuItem("Delete", KeyEvent.VK_D));
jmi.addActionListener(new deleteL());
edit.addSeparator();
edit.add(jmi = new JMenuItem("Select All", KeyEvent.VK_A));
jmi.addActionListener(new selectAllL());

search.add(jmi = new JMenuItem("Find", KeyEvent.VK_F));
jmi.addActionListener(new findL());
search.add(jmi = new JMenuItem("Find Next", KeyEvent.VK_N));
jmi.addActionListener(new findNextL());

help.add(jmi = new JMenuItem("About", KeyEvent.VK_A));
jmi.addActionListener(new aboutL());

setLayout(new BorderLayout());
file.setMnemonic(KeyEvent.VK_F);
jmb.add(file);
edit.setMnemonic(KeyEvent.VK_E);
jmb.add(edit);
search.setMnemonic(KeyEvent.VK_S);
jmb.add(search);
jmb.add(Box.createHorizontalGlue());
help.setMnemonic(KeyEvent.VK_H);
jmb.add(help);

toolBar.setFloatable(true);
addButtons(toolBar);

add(jmb, BorderLayout.NORTH);
add(toolBar, BorderLayout.CENTER);
add(jsp, BorderLayout.SOUTH);

jta.getCaret().setVisible(true);
jta.setCaretPosition(0);
}

public static void main(String args[])
{
JFrame f = new JFrame();
JNotepad applet = new JNotepad();
f.setTitle("JNotepad");
f.setBackground(Color.lightGray);
f.getContentPane().add(applet, BorderLayout.CENTER);
f.addWindowListener(new appCloseL());
f.setSize(800, 500);
f.setVisible(true);
f.pack();
}

protected void addButtons(JToolBar toolBar)
{
JButton button = new JButton(new ImageIcon("images/new.gif"));
button.setToolTipText("Create a new document");
button.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
jta.setDocument(new PlainDocument());
}
});
toolBar.add(button);

JButton button1 = new JButton(new ImageIcon("images/open.gif"));
button1.setToolTipText("Open a document");
button1.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
JFileChooser fc = new JFileChooser();
int returnVal = fc.showDialog(JNotepad.this, "Open file");
if(returnVal == JFileChooser.APPROVE_OPTION)
{
String file = fc.getSelectedFile().getPath();
if(file == null)
{
return;
}
try
{
Reader in = new FileReader(file);
char[] buff = new char[4096];
int nch;
while((nch = in.read(buff, 0, buff.length)) != -1)
{
jta.setDocument(new PlainDocument());
jta.append(new String(buff, 0, nch));
}
}
catch (IOException io)
{
System.err.println("IOException: " + io.getMessage());
}
}
else
{
return;
}
}
});
toolBar.add(button1);

JButton button2 = new JButton(new ImageIcon("images/save.gif"));
button2.setToolTipText("Save the document");
button2.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
JFileChooser fc = new JFileChooser();
int returnVal = fc.showSaveDialog(JNotepad.this);
if(returnVal == JFileChooser.APPROVE_OPTION)
{
String savefile = fc.getSelectedFile().getPath();
if(savefile == null)
{
return;
}
else
{
String docToSave = jta.getText();
if(docToSave != null)
{
FileOutputStream fstrm = null;
BufferedOutputStream ostrm = null;
try
{
fstrm = new FileOutputStream(savefile);
ostrm = new BufferedOutputStream(fstrm);
byte[] bytes = null;
try
{
bytes = docToSave.getBytes();
}
catch(Exception e1)
{
e1.printStackTrace();
}
ostrm.write(bytes);
}
catch(IOException io)
{
System.err.println("IOException: " +
io.getMessage());
}
finally
{
try
{
ostrm.flush();
fstrm.close();
ostrm.close();
}
catch(IOException ioe)
{
System.err.println("IOException: " +
ioe.getMessage());
}
}
}
}
}
else
{
return;
}
}
});
toolBar.add(button2);

JButton button3 = new JButton(new ImageIcon("images/copy.gif"));
button3.setToolTipText("Copy selected text");
button3.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String selection = jta.getSelectedText();
StringSelection clipString = new StringSelection(selection);
clipbd.setContents(clipString, clipString);
}
});
toolBar.add(button3);

JButton button4 = new JButton(new ImageIcon("images/cut.gif"));
button4.setToolTipText("Cut selected text");
button4.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String selection = jta.getSelectedText();
StringSelection clipString = new StringSelection(selection);
clipbd.setContents(clipString, clipString);
jta.replaceRange("", jta.getSelectionStart(),
jta.getSelectionEnd());
}
});
toolBar.add(button4);

JButton button5 = new JButton(new ImageIcon("images/paste.gif"));
button5.setToolTipText("Paste clipboard");
button5.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
Transferable clipData = clipbd.getContents(JNotepad.this);
try
{
String clipString =
(String)clipData.getTransferData(
DataFlavor.stringFlavor);
jta.replaceRange(clipString,
jta.getSelectionStart(), jta.getSelectionEnd());
}
catch(Exception ex)
{
}
}
});
toolBar.add(button5);

JButton button6 = new JButton(new ImageIcon("images/about.gif"));
button6.setToolTipText("About application");
button6.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
JOptionPane.showMessageDialog(null,
"JNotepad Developed By thyokel");
}
});
toolBar.add(button6);
}

protected static final class appCloseL extends WindowAdapter
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
}