JAVA高手请进！！！急！！！ 截取部分代码，请见谅！！！无法实现保存功能，请高手指教，谢谢！！！

public class NoteBook extends JFrame implements ActionListener{
private JMenuBar menubar;
private JMenu File,Edit;
private JMenuItem newFile,openFile,dosave,saveOtherFile;
private JTextArea text;
private JFileChooser chooser;
private File file;
private String saveFiles="",openFiles="";
private boolean ziding=true;
private int second;
private boolean result=false,flag=false;
JLabel hang;
JLabel time;
public NoteBook()
{
super("计算机");
menubar=new JMenuBar();
setJMenuBar(menubar);
File=new JMenu("文件");

newFile=new JMenuItem("新建");
openFile=new JMenuItem("打开");
dosave=new JMenuItem("保存");
saveOtherFile=new JMenuItem("另存为");
Edit=new JMenu("编辑");
cut=new JMenuItem("剪切");
copy=new JMenuItem("复制");
paste=new JMenuItem("粘贴");
date=new JMenuItem("时间/日期");
File.add(newFile);
File.add(openFile);
File.add(dosave);
File.add(saveOtherFile);
Edit.add(cut);
Edit.add(copy);
Edit.add(paste);
Edit.add(date);
menubar.add(File);
menubar.add(Edit);
text=new JTextArea(50,100);
newFile.addActionListener(this);
openFile.addActionListener(this);
dosave.addActionListener(this);
saveOtherFile.addActionListener(this);
cut.addActionListener(this);
copy.addActionListener(this);
paste.addActionListener(this);
date.addActionListener(this);
add(text);
setSize(600,500);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);public void dosave()
{
if(result)
{
try
{
if(file.exists())
{
file.delete();
}
else
{
FileOutputStream fos=new FileOutputStream(file+ ".txt");
OutputStreamWriter osw=new OutputStreamWriter(fos);
String saveString=text.getText().replaceAll("\n","\r\n");
osw.append(saveString);
osw.flush();
osw.close();
}
saveFiles=text.getText();
}catch(Exception e)
{
e.printStackTrace();
}
}
else
{
saveOtherFile();
}
}
public void saveOtherFile()
{
int i=chooser.showSaveDialog(null);
if(i==JFileChooser.APPROVE_OPTION)
{
file=chooser.getSelectedFile();
String savestring=text.getText().replaceAll("\n","\r'n");
try
{
PrintWriter output=new PrintWriter(new FileOutputStream(file.getPath()+".txt"));
output.print(savestring);
output.close();
saveFiles=text.getText();
result=true;
}
catch(IOException e)
{
e.printStackTrace();
}
if(i==JOptionPane.CANCEL_OPTION)
{
ziding=false;
}
}

}
public void actionPerformed(ActionEvent e)
{
String s=(e.getActionCommand());
String str=text.getText(); else if(s.equals("保存"))
{
dosave();
}
else if(s.equals("另存为"))
{
saveOtherFile();
}
}
public static void main(String args[])
{
new NoteBook();
}
}