Java implementation simple notepad

Including opening, saving, copying, pasting, and cutting files, all functions are implemented on the menu bar.

Source code:

 
import java.awt. *;
import java.awt.event. *;
import java.io. *;
import javax.swing. *;
import javax.swing.event. *;
import javax.swing.filechooser.FileFilter;
import static java.awt.event.InputEvent. *;
import java.awt.datatransfer. *;
import java.util.Enumeration;
import java.util.Hashtable;
/ * import javax.swing. *;
import javax.swing.filechooser.FileFilter;

import java.awt.event. *;
import java.awt. *;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException; * /

class jishiben
{
  public static void main (String args [])
  {
     TextEdit TE = new TextEdit ("Notepad");
  }
}
class TextEdit extends Frame implements ActionListener
{
   MenuBar m;
   Menu m1, m2;
   MenuItem xinjian, dakai, baocun, tuichu, jianqie, fuzhi, zhantie;
   TextArea text;
   String filename;
   FileDialog openFD, saveFD;
   BufferedReader in;
   FileReader read;
   BufferedWriter out;
   FileWriter writer;
   Clipboard cb;
   TextEdit (String s)
   {
     super (s);
     m = new MenuBar ();
     m1 = new Menu ("File");
     xinjian = new MenuItem ("New");
     dakai = new MenuItem ("Open");
     baocun = new MenuItem ("Save");
     tuichu = new MenuItem ("Exit");
     m2 = new Menu ("Edit");
     jianqie = new MenuItem ("Cut");
     fuzhi = new MenuItem ("Copy");
     zhantie = new MenuItem ("Paste");
     text = new TextArea ();
     openFD = new FileDialog (this, "Open", FileDialog.LOAD);
     saveFD = new FileDialog (this, "Save", FileDialog.SAVE);
     filename = "NoName";
     
     m1.add (xinjian);
     m1.addSeparator ();
     m1.add (dakai);
     m1.addSeparator ();
     m1.add (baocun);
     m1.addSeparator ();
     m1.add (tuichu);
     m2.add (jianqie);
     m2.addSeparator ();
     m2.add (fuzhi);
     m2.addSeparator ();
     m2.add (zhantie);
     m.add (m1);
     m.add (m2);
     
     // Key part, no memory is applied for cb, the following cb operation error
    cb = new Clipboard ("nothing");
     //
     
     setMenuBar (m);
     setSize (300,400); setVisible (true);
     add (text, "Center");
     
     xinjian.addActionListener (this);
     dakai.addActionListener (this);
     baocun.addActionListener (this);
     tuichu.addActionListener (this);
     jianqie.addActionListener (this);
     fuzhi.addActionListener (this);
     zhantie.addActionListener (this);
     addWindowListener (new WindowAdapter ()
                      {
                        public void windowClosing (WindowEvent e)
                        {
                          System.exit (0);
                        }
                      });
    }
    
    public void actionPerformed (ActionEvent e)
    {
      if (e.getSource () == xinjian)
       {
         text.setText ("");
       }
      if (e.getSource () == dakai)
       {
        openFD.show ();
        String s;
        filename = openFD.getDirectory () + openFD.getFile ();
        if (filename! = null)
         {
          try
           {
            File file = new File (filename);
            read = new FileReader (file);
            in = new BufferedReader (read);
            while ((s = in.readLine ())! = null)
                text.append (s + '\ n');
            in.close ();
            read.close ();
           }
            catch (IOException e2) {}
         }
       }
      
      if (e.getSource () == baocun)
      {
        saveFD.show ();
        filename = saveFD.getDirectory () + saveFD.getFile ();
        if (filename! = null)
        {
         try
           {
            File file = new File (filename);
            writer = new FileWriter (file);
            out = new BufferedWriter (writer);
            out.write (text.getText (), 0, (text.getText ()). length ());
            
            out.close ();
            writer.close ();
           }
          catch (IOException e2) {}
        }
      }
      if (e.getSource () == tuichu)
      {
        System.exit (0);
      }
      
      
      
      
     if (e.getSource () == jianqie)
      {
      // There is no cut method in class text, you cannot use text.cut
        String s = text.getSelectedText ();
        StringSelection select = new StringSelection (s);
        cb.setContents (select, null);
        text.replaceRange ("", text.getSelectionStart (), text.getSelectionEnd ());
      }
      if (e.getSource () == fuzhi)
      {
      // Same as above, there is no copy method
        String s = text.getSelectedText ();
        StringSelection select = new StringSelection (s);
        cb.setContents (select, null);
      }
      if (e.getSource () == zhantie)
      {
      // Same as above, no paste method
           String s = "";
          Transferable t = cb.getContents (null);
          try
          {
                if (t! = null
                    && t.isDataFlavorSupported (DataFlavor.stringFlavor))
                {
                        // Because there are many kinds of information in the original clipboard, such as text, pictures, files, etc.
                        // First determine whether the data that can be transmitted is the text, and if so, get the text
                        
                    s = (String) t.getTransferData (DataFlavor.stringFlavor);
                        // Similarly, because the DataFlavor in Transferable is of multiple types,
                        // So pass the DataFlavor parameter, which specifies what type of Data to get.
                        //System.out.println(s);
}
           }
           catch (UnsupportedFlavorException ex)
           {
                 ex.printStackTrace ();
           }
           catch (IOException ex)
           {
                 ex.printStackTrace ();
           }
          
           text.insert (s, text.getCaretPosition ());
          
       }
      
     }
  
   
}