java编写一个记事本小程序，接着下面的代码写，求大神解救！实现新建，保存，打开功能就行！

package tuxingjiemian;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.io.PrintStream;
public class jishiben extends JFrame {
JPanel jp=new JPanel();
JFrame find_replace=new JFrame();
JMenu file=new JMenu("文件");
JMenu edit=new JMenu("编辑");
JMenu help=new JMenu("帮助");
JMenuBar menubar=new JMenuBar();
JTextArea aa=new JTextArea();
class Open implements ActionListener {
public void actionPerformed(ActionEvent e) {
JFileChooser jf= new JFileChooser();
jf.showOpenDialog(jishiben.this);
try {
PrintStream p=new PrintStream(jf.getSelectedFile().getPath());
} catch (Exception e2) {
}
}
}
class Save implements ActionListener {
public void actionPerformed(ActionEvent e) {
JFileChooser jf= new JFileChooser();
jf.showSaveDialog(jishiben.this);
try {
PrintStream p=new PrintStream(jf.getSelectedFile().getPath());
} catch (Exception e2) {
}
}
}
public jishiben(){
this.setTitle("记事本");
this.setSize(500, 500);
this.setLayout(new BorderLayout());
JMenuItem open=new JMenuItem("打开");
open.addActionListener(new Open());
JMenuItem save=new JMenuItem("保存");
save.addActionListener(new Save());
JMenuItem exit=new JMenuItem("退出");
exit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.exit(0);

}
});
file.add(open);
file.add(save);
file.addSeparator();
file.add(exit);
menubar.add(file);
this.add(new JScrollPane(aa),BorderLayout.CENTER);
JMenuItem copy=new JMenuItem("复制");
JMenuItem past=new JMenuItem("粘贴");
JMenuItem delete=new JMenuItem("删除");
JMenuItem find=new JMenuItem("查找");
JMenuItem replace=new JMenuItem("替换");
copy.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
jishiben.this.aa.copy();
}
});
past.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
jishiben.this.aa.paste();
}
});

delete.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jishiben.this.aa.replaceSelection(null);
}
});
edit.add(copy);
edit.add(past);
edit.add(delete);
edit.add(find);
edit.add(replace);
menubar.add(edit);
help.add(new JMenuItem("帮助"));
menubar.add(help);
this.add(menubar,BorderLayout.NORTH);
this.setVisible(true);
this.setDefaultCloseOperation(this.EXIT_ON_CLOSE);
}

public static void main(String[] args) {
new jishiben();
}
};