How to make a Notepad app in ThinkJava

How to make a Notepad app in ThinkJava
Hi! Today, me, the founder and dev of ThinkJava, Zean, here to teach you how to make a Notepad app that you recognize in your PC.
Want to make one? Follow me and I will guide you on this adventure on to make notepad.

1. Prepare a new project
I know you already know how to make a new project. Let's name this new shiny project Notepad in Java
Then, make a class called Notepad.
2. Write the code
From now, in the class we have to write this line. We are going to use javax.swing so head to Window > Marketplace then go to Packages then download and install Java Framework Tools. Now you can start writing this line of code.
We need to make sure to import all the javax by writing this line of code.

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.datatransfer.*;
import java.io.*;
import javax.swing.undo.*;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;
import javax.swing.text.Highlighter.HighlightPainter;

Okay now we have initialized the damn stuffs, let's get to the real coding.
Write these statements inside the class.
Don't forget to write these statements next to the public class Notepad

public class Notepad extends JFrame

Next, we write these statements inside the class.

     String filename;
     JTextPane tx;
     Clipboard clip = getToolkit().getSystemClipboard();
     JColorChooser chooser = new JColorChooser(Color.WHITE);
     UndoManager manager = new UndoManager();
    Action undoAction = new UndoAction(manager);
    Action redoAction = new RedoAction(manager);
    JDialog finddiag;
    JTextField getfindword;
    HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter(Color.orange);

      Notepad()
       {
         setLayout(new GridLayout(1,1));
         //create new TextArea & add it ti JFrame
         tx = new JTextPane();
         JScrollPane jscrollp=new JScrollPane(tx);
         tx.getDocument().addUndoableEditListener(manager);
         add(jscrollp);
         //Create JMenuBar
         JMenuBar mb = new JMenuBar();
         //Create File menu
         JMenu F = new JMenu(" File ");
         F.setFont(new Font("Segoe UI",Font.PLAIN,12));
         //File->New
         JMenuItem n = new JMenuItem("New                             ");
         n.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N,ActionEvent.CTRL_MASK));
         //File->Open
         JMenuItem o = new JMenuItem("Open");
         o.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,ActionEvent.CTRL_MASK));
         //File->Save
         JMenuItem s = new JMenuItem("Save");
         s.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,ActionEvent.CTRL_MASK));
         //File->Exit
         JMenuItem e = new JMenuItem("Exit");
         //add action listener to menu items and add those to F
         n.addActionListener(new New());
         F.add(n);
         F.addSeparator();
         o.addActionListener(new Open());
         F.add(o);
         F.addSeparator();
         s.addActionListener(new Save());
         F.add(s);
         F.addSeparator();
         e.addActionListener(new Exit());
         F.add(e);
         mb.add(F);
         //Create Edit menu
         JMenu E = new JMenu(" Edit ");
         E.setFont(new Font("Segoe UI",Font.PLAIN,12));
         //Edit->Cut
         JMenuItem cut = new JMenuItem("Cut                         ");
         cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,ActionEvent.CTRL_MASK));
         //Edit->Copy
         JMenuItem copy = new JMenuItem("Copy");
         copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,ActionEvent.CTRL_MASK));
         //Edit->Paste
         JMenuItem paste = new JMenuItem("Paste");
         paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V,ActionEvent.CTRL_MASK));
         //Edit->Undo
         JMenuItem undo = new JMenuItem("Undo");
         undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z,ActionEvent.CTRL_MASK));
         //Edit->Redo
         JMenuItem redo = new JMenuItem("Redo");
         redo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Y,ActionEvent.CTRL_MASK));
         //Edit->Find
         JMenuItem find=new JMenuItem("Find");
         //Edit->Select All
         JMenuItem selectall=new JMenuItem("Select All");
         selectall.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A,ActionEvent.CTRL_MASK));
         //Edit->Text Color
         JMenuItem textcolor=new JMenuItem("Text Color");
         //Edit->Back Color
         JMenuItem backcolor=new JMenuItem("Back Color");

         cut.addActionListener(new Cut());
         E.add(cut);
         copy.addActionListener(new Copy());
         E.add(copy);
         paste.addActionListener(new Paste());
         E.add(paste);
         E.addSeparator();
         undo.addActionListener(undoAction);
         E.add(undo);
         redo.addActionListener(redoAction);
         E.add(redo);
         E.addSeparator();
         find.addActionListener(new Find());
         E.add(find);
         E.addSeparator();
         selectall.addActionListener(new SelectAll());
         E.add(selectall);
         E.addSeparator();
         textcolor.addActionListener(new TextColorAction());
         E.add(textcolor);
         backcolor.addActionListener(new BackColorAction());
         E.add(backcolor);
         mb.add(E);
         //Create Font menu
         JMenu font=new JMenu(" Font ");
         font.setFont(new Font("Segoe UI",Font.PLAIN,12));
         JMenuItem plain=new JMenuItem("Plain                               ");
         JMenuItem bold=new JMenuItem("Bold");
         JMenuItem italic=new JMenuItem("Italic");
         JMenuItem plainbold=new JMenuItem("Plain+Bold");
         JMenuItem plainitalic=new JMenuItem("Plain+Italic");
         JMenuItem bolditalic=new JMenuItem("Bold+Italic");
         JMenuItem fontsize=new JMenuItem("Font Size");
         plain.addActionListener(new FontPlainAction());
         bold.addActionListener(new FontBoldAction());
         italic.addActionListener(new FontItalicAction());
         plainbold.addActionListener(new FontPlainBoldAction());
         plainitalic.addActionListener(new FontPlainItalicAction());
         bolditalic.addActionListener(new FontBoldItalicAction());
         fontsize.addActionListener(new FontSizeAction());
         font.add(plain);
         font.add(bold);
         font.add(italic);
         font.add(plainbold);
         font.add(plainitalic);
         font.add(bolditalic);
         font.add(fontsize);
         mb.add(font);
         //Create Help Menu
         JMenu help=new JMenu(" Help ");
         help.setFont(new Font("Segoe UI",Font.PLAIN,12));
         JMenuItem about=new JMenuItem("About              ");
         about.addActionListener(new AboutAction());
         help.add(about);
         mb.add(help);
         setJMenuBar(mb);
         mylistener mylist = new mylistener();
         addWindowListener(mylist);
     }


      //Class AboutAction
     class AboutAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
        JOptionPane.showMessageDialog(null, "Notepad in Java", "About Notepad",JOptionPane.INFORMATION_MESSAGE);
    }
  }


     //Class Font Plain Action
     class FontPlainAction implements ActionListener
     {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN,14));
        }
 }


     //Class Font Bold Action
     class FontBoldAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.BOLD,14));
        }
 }


     //Class Font Italic Action
     class FontItalicAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.ITALIC,14));
        }
 }


     //Class Font Plain Bold Action
     class FontPlainBoldAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN+Font.BOLD,20));
        }
 }


     //Class Font Plain Italic Action
     class FontPlainItalicAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN+Font.ITALIC,20));
        }
 }


     //Class Font Bold Italic Action
     class FontBoldItalicAction  implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.BOLD+Font.ITALIC,20));
        }
 }


     //Class Font Size Action
 class FontSizeAction implements ActionListener
 {
     public void actionPerformed(ActionEvent e)
     {
         String x=JOptionPane.showInputDialog(null, "Enter Font Size :","Input Dialog",JOptionPane.OK_CANCEL_OPTION);
         int i=Integer.parseInt(x);
         tx.setFont(new Font("Serif",Font.PLAIN,i));
    }
}


 //Class mylistener
     class mylistener extends WindowAdapter
         {
         public void windowClosing (WindowEvent e)
             {
             System.exit(0);
         }
     }


     //Class New
     class New implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             tx.setText("");
              setTitle("Notepad in Java");
         }
     }


     //Class Open
     class Open implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             FileDialog fd = new FileDialog(Notepad.this, "Select File",FileDialog.LOAD);
             fd.show();
             if (fd.getFile()!=null)
                 {
                 filename = fd.getDirectory() + fd.getFile();
                 setTitle(filename);
                 ReadFile();
             }
             tx.requestFocus();
         }
     }


     //Class Save
     class Save implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             FileDialog fd = new FileDialog(Notepad.this,"Save File",FileDialog.SAVE);
             fd.show();
             if (fd.getFile()!=null)
                 {
                 filename = fd.getDirectory() + fd.getFile();
                 setTitle(filename);
                 try
                     {
                     DataOutputStream d = new DataOutputStream(new FileOutputStream(filename));
                     String line = tx.getText();
                     BufferedReader br = new BufferedReader(new StringReader(line));
                     while((line = br.readLine())!=null)
                         {
                         d.writeBytes(line+"\n");
                     }
                 }
                 catch(Exception ex)
                     {
                     System.out.println("File not found");
                 }
                 tx.requestFocus();
             }
         }
     }


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


     //ReadFile() function
     void ReadFile()
         {
         BufferedReader d;
         StringBuffer sb = new StringBuffer();
         try
             {
             d = new BufferedReader(new FileReader(filename));
             String line;
             while((line=d.readLine())!=null)
             sb.append(line + "\n");
             tx.setText(sb.toString());
             d.close();
         }
         catch(FileNotFoundException fe)
             {
             System.out.println("File not Found");
         }
         catch(IOException ioe){}
     }


//Class Cut
     class Cut implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             String sel = tx.getSelectedText();
             StringSelection ss = new StringSelection(sel);
             clip.setContents(ss,ss);
             tx.replaceSelection(sel);
         }
     }


     //Class Copy
     class Copy implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             String sel = tx.getSelectedText();
             StringSelection clipString = new StringSelection(sel);
             clip.setContents(clipString,clipString);
         }
     }


     //Class Paste
     class Paste implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             Transferable cliptran = clip.getContents(Notepad.this);
             try
                 {
                 String sel = (String) cliptran.getTransferData(DataFlavor.stringFlavor);
                 tx.replaceSelection(sel);
             }
             catch(Exception exc)
                 {
                 System.out.println("not string flavour");
             }
         }
     }

     // Class Undo action
     public class UndoAction extends AbstractAction
     {
         UndoManager manager;
       public UndoAction(UndoManager manager)
       {
         this.manager = manager;
       }
     public void actionPerformed(ActionEvent evt)
     {
         try
         {
           manager.undo();
         }
         catch (CannotUndoException e)
         {
           Toolkit.getDefaultToolkit().beep();
         }
       }
     }


     //Class Redo action
     public class RedoAction extends AbstractAction
     {
         UndoManager manager;
       public RedoAction(UndoManager manager)
       {
         this.manager = manager;
       }
       public void actionPerformed(ActionEvent evt)
       {
         try
         {
           manager.redo();
         }
         catch (CannotRedoException e)
         {
           Toolkit.getDefaultToolkit().beep();
         }
       }
     }

     //Class Find
     class Find implements ActionListener
     {
           JLabel getwordlabel;
         public void actionPerformed(ActionEvent evt)
         {
             finddiag=new JDialog(new JDialog(),true);
             finddiag.setSize(300,100);
             finddiag.setResizable(false);
             finddiag.setTitle("Find.......");
             finddiag.setLocation(300,200);
             finddiag.setAlwaysOnTop(true);
             finddiag.setLayout(new FlowLayout());
             getwordlabel=new JLabel("Find What ?");
             getwordlabel.setFont(new Font("Lucida",Font.PLAIN,14));
             getfindword=new JTextField(13);
             getfindword.setFont(new Font("Lucida",Font.PLAIN,12));
             JButton finddone=new JButton("Find");
             finddone.setFont(new Font("Lucida",Font.PLAIN,14));
             finddone.addActionListener(new FindDoneAction());
             JButton findclose=new JButton("Close");
             findclose.setFont(new Font("Lucida",Font.PLAIN,14));
             findclose.addActionListener(new FindCloseAction());
             finddiag.add(getwordlabel);
             finddiag.add(getfindword);
             finddiag.add(finddone);
             finddiag.add(findclose);
             finddiag.setVisible(true);
         }
     }
     class FindDoneAction implements ActionListener
     {
         public void actionPerformed(ActionEvent replacedoneEvt)
         {
             String getword=getfindword.getText();
             int start=tx.getText().indexOf(getword);
             int end=getword.length();
              if(start>=0 && getword.length()>0)
             {
               tx.select(start,start+end);
                      try
              {
             Highlighter highlighter = tx.getHighlighter();
              highlighter.addHighlight(start, start+end, painter );
              }
              catch(Exception ex){}
              }
             }
         }
     class FindCloseAction implements ActionListener
     {
         public void actionPerformed(ActionEvent replacedoneEvt)
         {
             finddiag.setVisible(false);
          }
     }

     class SelectAll implements ActionListener
     {
        public void actionPerformed(ActionEvent e)
        {
                  tx.selectAll();
        }
     }

     //Class Text Color
     class TextColorAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
               JDialog jc1=new JDialog(new JDialog(),true);
               jc1.setSize(500,400);
               jc1.setLocation(160,100);
               jc1.setResizable(false);
               jc1.setTitle("Select Color");
               jc1.setLayout(new BorderLayout());
               JButton done=new JButton("Done");
               done.setBackground(Color.WHITE);
               done.setToolTipText("Set Background Color to Menu Bar");
               done.setFont(new Font("Constantia",Font.PLAIN+Font.BOLD,16));
               jc1.add(chooser,BorderLayout.NORTH);
               jc1.add(done,BorderLayout.SOUTH);
               done.addActionListener(new TextColorDoneButtonAction());
               jc1.setVisible(true);
         }
     }
     class TextColorDoneButtonAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
             Color mbcolor=chooser.getColor();
             tx.setForeground(mbcolor);
         }
     }

     //Class Back Color
     class BackColorAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
           JDialog jc1=new JDialog(new JDialog(),true);
           jc1.setSize(500,400);
           jc1.setLocation(160,100);
           jc1.setResizable(false);
           jc1.setTitle("Select Color");
           jc1.setLayout(new BorderLayout());
           JButton done=new JButton("Done");
           done.setBackground(Color.WHITE);
           done.setToolTipText("Set Background Color to Menu Bar");
           done.setFont(new Font("Constantia",Font.PLAIN+Font.BOLD,16));
           jc1.add(chooser,BorderLayout.NORTH);
           jc1.add(done,BorderLayout.SOUTH);
           done.addActionListener(new BackColorDoneButtonAction());
           jc1.setVisible(true);
         }
     }
     class BackColorDoneButtonAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
             Color mbcolor=chooser.getColor();
             tx.setBackground(mbcolor);
         }
     }

     //main method
     public static void main(String args[])
      {
          try
            {
             UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
            }
            catch (Exception e)
            {
              e.printStackTrace();
            }
         JFrame jf = new Notepad();
         jf.setTitle("Notepad in Java");
         jf.setExtendedState(6);
         jf.setSize(800,600);
         jf.setVisible(true);
     }

So, here is the full code, you smart devs.

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.datatransfer.*;
import java.io.*;
import javax.swing.undo.*;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;
import javax.swing.text.Highlighter.HighlightPainter;

public class Notepad extends JFrame
    {
     String filename;
     JTextPane tx;
     Clipboard clip = getToolkit().getSystemClipboard();
     JColorChooser chooser = new JColorChooser(Color.WHITE);
     UndoManager manager = new UndoManager();
    Action undoAction = new UndoAction(manager);
    Action redoAction = new RedoAction(manager);
    JDialog finddiag;
    JTextField getfindword;
    HighlightPainter painter = new DefaultHighlighter.DefaultHighlightPainter(Color.orange);

      Notepad()
       {
         setLayout(new GridLayout(1,1));
         //create new TextArea & add it ti JFrame
         tx = new JTextPane();
         JScrollPane jscrollp=new JScrollPane(tx);
         tx.getDocument().addUndoableEditListener(manager);
         add(jscrollp);
         //Create JMenuBar
         JMenuBar mb = new JMenuBar();
         //Create File menu
         JMenu F = new JMenu(" File ");
         F.setFont(new Font("Segoe UI",Font.PLAIN,12));
         //File->New
         JMenuItem n = new JMenuItem("New                             ");
         n.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N,ActionEvent.CTRL_MASK));
         //File->Open
         JMenuItem o = new JMenuItem("Open");
         o.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,ActionEvent.CTRL_MASK));
         //File->Save
         JMenuItem s = new JMenuItem("Save");
         s.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S,ActionEvent.CTRL_MASK));
         //File->Exit
         JMenuItem e = new JMenuItem("Exit");
         //add action listener to menu items and add those to F
         n.addActionListener(new New());
         F.add(n);
         F.addSeparator();
         o.addActionListener(new Open());
         F.add(o);
         F.addSeparator();
         s.addActionListener(new Save());
         F.add(s);
         F.addSeparator();
         e.addActionListener(new Exit());
         F.add(e);
         mb.add(F);
         //Create Edit menu
         JMenu E = new JMenu(" Edit ");
         E.setFont(new Font("Segoe UI",Font.PLAIN,12));
         //Edit->Cut
         JMenuItem cut = new JMenuItem("Cut                         ");
         cut.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_X,ActionEvent.CTRL_MASK));
         //Edit->Copy
         JMenuItem copy = new JMenuItem("Copy");
         copy.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_C,ActionEvent.CTRL_MASK));
         //Edit->Paste
         JMenuItem paste = new JMenuItem("Paste");
         paste.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_V,ActionEvent.CTRL_MASK));
         //Edit->Undo
         JMenuItem undo = new JMenuItem("Undo");
         undo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Z,ActionEvent.CTRL_MASK));
         //Edit->Redo
         JMenuItem redo = new JMenuItem("Redo");
         redo.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Y,ActionEvent.CTRL_MASK));
         //Edit->Find
         JMenuItem find=new JMenuItem("Find");
         //Edit->Select All
         JMenuItem selectall=new JMenuItem("Select All");
         selectall.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_A,ActionEvent.CTRL_MASK));
         //Edit->Text Color
         JMenuItem textcolor=new JMenuItem("Text Color");
         //Edit->Back Color
         JMenuItem backcolor=new JMenuItem("Back Color");

         cut.addActionListener(new Cut());
         E.add(cut);
         copy.addActionListener(new Copy());
         E.add(copy);
         paste.addActionListener(new Paste());
         E.add(paste);
         E.addSeparator();
         undo.addActionListener(undoAction);
         E.add(undo);
         redo.addActionListener(redoAction);
         E.add(redo);
         E.addSeparator();
         find.addActionListener(new Find());
         E.add(find);
         E.addSeparator();
         selectall.addActionListener(new SelectAll());
         E.add(selectall);
         E.addSeparator();
         textcolor.addActionListener(new TextColorAction());
         E.add(textcolor);
         backcolor.addActionListener(new BackColorAction());
         E.add(backcolor);
         mb.add(E);
         //Create Font menu
         JMenu font=new JMenu(" Font ");
         font.setFont(new Font("Segoe UI",Font.PLAIN,12));
         JMenuItem plain=new JMenuItem("Plain                               ");
         JMenuItem bold=new JMenuItem("Bold");
         JMenuItem italic=new JMenuItem("Italic");
         JMenuItem plainbold=new JMenuItem("Plain+Bold");
         JMenuItem plainitalic=new JMenuItem("Plain+Italic");
         JMenuItem bolditalic=new JMenuItem("Bold+Italic");
         JMenuItem fontsize=new JMenuItem("Font Size");
         plain.addActionListener(new FontPlainAction());
         bold.addActionListener(new FontBoldAction());
         italic.addActionListener(new FontItalicAction());
         plainbold.addActionListener(new FontPlainBoldAction());
         plainitalic.addActionListener(new FontPlainItalicAction());
         bolditalic.addActionListener(new FontBoldItalicAction());
         fontsize.addActionListener(new FontSizeAction());
         font.add(plain);
         font.add(bold);
         font.add(italic);
         font.add(plainbold);
         font.add(plainitalic);
         font.add(bolditalic);
         font.add(fontsize);
         mb.add(font);
         //Create Help Menu
         JMenu help=new JMenu(" Help ");
         help.setFont(new Font("Segoe UI",Font.PLAIN,12));
         JMenuItem about=new JMenuItem("About              ");
         about.addActionListener(new AboutAction());
         help.add(about);
         mb.add(help);
         setJMenuBar(mb);
         mylistener mylist = new mylistener();
         addWindowListener(mylist);
     }


      //Class AboutAction
     class AboutAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
        JOptionPane.showMessageDialog(null, "Notepad in Java", "About Notepad",JOptionPane.INFORMATION_MESSAGE);
    }
  }


     //Class Font Plain Action
     class FontPlainAction implements ActionListener
     {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN,14));
        }
 }


     //Class Font Bold Action
     class FontBoldAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.BOLD,14));
        }
 }


     //Class Font Italic Action
     class FontItalicAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.ITALIC,14));
        }
 }


     //Class Font Plain Bold Action
     class FontPlainBoldAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN+Font.BOLD,20));
        }
 }


     //Class Font Plain Italic Action
     class FontPlainItalicAction implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.PLAIN+Font.ITALIC,20));
        }
 }


     //Class Font Bold Italic Action
     class FontBoldItalicAction  implements ActionListener
      {
        public void actionPerformed(ActionEvent e)
        {
                  tx.setFont(new Font("Serif",Font.BOLD+Font.ITALIC,20));
        }
 }


     //Class Font Size Action
 class FontSizeAction implements ActionListener
 {
     public void actionPerformed(ActionEvent e)
     {
         String x=JOptionPane.showInputDialog(null, "Enter Font Size :","Input Dialog",JOptionPane.OK_CANCEL_OPTION);
         int i=Integer.parseInt(x);
         tx.setFont(new Font("Serif",Font.PLAIN,i));
    }
}


 //Class mylistener
     class mylistener extends WindowAdapter
         {
         public void windowClosing (WindowEvent e)
             {
             System.exit(0);
         }
     }


     //Class New
     class New implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             tx.setText("");
              setTitle("Notepad in Java");
         }
     }


     //Class Open
     class Open implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             FileDialog fd = new FileDialog(Notepad.this, "Select File",FileDialog.LOAD);
             fd.show();
             if (fd.getFile()!=null)
                 {
                 filename = fd.getDirectory() + fd.getFile();
                 setTitle(filename);
                 ReadFile();
             }
             tx.requestFocus();
         }
     }


     //Class Save
     class Save implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             FileDialog fd = new FileDialog(Notepad.this,"Save File",FileDialog.SAVE);
             fd.show();
             if (fd.getFile()!=null)
                 {
                 filename = fd.getDirectory() + fd.getFile();
                 setTitle(filename);
                 try
                     {
                     DataOutputStream d = new DataOutputStream(new FileOutputStream(filename));
                     String line = tx.getText();
                     BufferedReader br = new BufferedReader(new StringReader(line));
                     while((line = br.readLine())!=null)
                         {
                         d.writeBytes(line+"\n");
                     }
                 }
                 catch(Exception ex)
                     {
                     System.out.println("File not found");
                 }
                 tx.requestFocus();
             }
         }
     }


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


     //ReadFile() function
     void ReadFile()
         {
         BufferedReader d;
         StringBuffer sb = new StringBuffer();
         try
             {
             d = new BufferedReader(new FileReader(filename));
             String line;
             while((line=d.readLine())!=null)
             sb.append(line + "\n");
             tx.setText(sb.toString());
             d.close();
         }
         catch(FileNotFoundException fe)
             {
             System.out.println("File not Found");
         }
         catch(IOException ioe){}
     }


//Class Cut
     class Cut implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             String sel = tx.getSelectedText();
             StringSelection ss = new StringSelection(sel);
             clip.setContents(ss,ss);
             tx.replaceSelection(sel);
         }
     }


     //Class Copy
     class Copy implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             String sel = tx.getSelectedText();
             StringSelection clipString = new StringSelection(sel);
             clip.setContents(clipString,clipString);
         }
     }


     //Class Paste
     class Paste implements ActionListener
         {
         public void actionPerformed(ActionEvent e)
             {
             Transferable cliptran = clip.getContents(Notepad.this);
             try
                 {
                 String sel = (String) cliptran.getTransferData(DataFlavor.stringFlavor);
                 tx.replaceSelection(sel);
             }
             catch(Exception exc)
                 {
                 System.out.println("not string flavour");
             }
         }
     }

     // Class Undo action
     public class UndoAction extends AbstractAction
     {
         UndoManager manager;
       public UndoAction(UndoManager manager)
       {
         this.manager = manager;
       }
     public void actionPerformed(ActionEvent evt)
     {
         try
         {
           manager.undo();
         }
         catch (CannotUndoException e)
         {
           Toolkit.getDefaultToolkit().beep();
         }
       }
     }


     //Class Redo action
     public class RedoAction extends AbstractAction
     {
         UndoManager manager;
       public RedoAction(UndoManager manager)
       {
         this.manager = manager;
       }
       public void actionPerformed(ActionEvent evt)
       {
         try
         {
           manager.redo();
         }
         catch (CannotRedoException e)
         {
           Toolkit.getDefaultToolkit().beep();
         }
       }
     }

     //Class Find
     class Find implements ActionListener
     {
           JLabel getwordlabel;
         public void actionPerformed(ActionEvent evt)
         {
             finddiag=new JDialog(new JDialog(),true);
             finddiag.setSize(300,100);
             finddiag.setResizable(false);
             finddiag.setTitle("Find.......");
             finddiag.setLocation(300,200);
             finddiag.setAlwaysOnTop(true);
             finddiag.setLayout(new FlowLayout());
             getwordlabel=new JLabel("Find What ?");
             getwordlabel.setFont(new Font("Lucida",Font.PLAIN,14));
             getfindword=new JTextField(13);
             getfindword.setFont(new Font("Lucida",Font.PLAIN,12));
             JButton finddone=new JButton("Find");
             finddone.setFont(new Font("Lucida",Font.PLAIN,14));
             finddone.addActionListener(new FindDoneAction());
             JButton findclose=new JButton("Close");
             findclose.setFont(new Font("Lucida",Font.PLAIN,14));
             findclose.addActionListener(new FindCloseAction());
             finddiag.add(getwordlabel);
             finddiag.add(getfindword);
             finddiag.add(finddone);
             finddiag.add(findclose);
             finddiag.setVisible(true);
         }
     }
     class FindDoneAction implements ActionListener
     {
         public void actionPerformed(ActionEvent replacedoneEvt)
         {
             String getword=getfindword.getText();
             int start=tx.getText().indexOf(getword);
             int end=getword.length();
              if(start>=0 && getword.length()>0)
             {
               tx.select(start,start+end);
                      try
              {
             Highlighter highlighter = tx.getHighlighter();
              highlighter.addHighlight(start, start+end, painter );
              }
              catch(Exception ex){}
              }
             }
         }
     class FindCloseAction implements ActionListener
     {
         public void actionPerformed(ActionEvent replacedoneEvt)
         {
             finddiag.setVisible(false);
          }
     }

     class SelectAll implements ActionListener
     {
        public void actionPerformed(ActionEvent e)
        {
                  tx.selectAll();
        }
     }

     //Class Text Color
     class TextColorAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
               JDialog jc1=new JDialog(new JDialog(),true);
               jc1.setSize(500,400);
               jc1.setLocation(160,100);
               jc1.setResizable(false);
               jc1.setTitle("Select Color");
               jc1.setLayout(new BorderLayout());
               JButton done=new JButton("Done");
               done.setBackground(Color.WHITE);
               done.setToolTipText("Set Background Color to Menu Bar");
               done.setFont(new Font("Constantia",Font.PLAIN+Font.BOLD,16));
               jc1.add(chooser,BorderLayout.NORTH);
               jc1.add(done,BorderLayout.SOUTH);
               done.addActionListener(new TextColorDoneButtonAction());
               jc1.setVisible(true);
         }
     }
     class TextColorDoneButtonAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
             Color mbcolor=chooser.getColor();
             tx.setForeground(mbcolor);
         }
     }

     //Class Back Color
     class BackColorAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
           JDialog jc1=new JDialog(new JDialog(),true);
           jc1.setSize(500,400);
           jc1.setLocation(160,100);
           jc1.setResizable(false);
           jc1.setTitle("Select Color");
           jc1.setLayout(new BorderLayout());
           JButton done=new JButton("Done");
           done.setBackground(Color.WHITE);
           done.setToolTipText("Set Background Color to Menu Bar");
           done.setFont(new Font("Constantia",Font.PLAIN+Font.BOLD,16));
           jc1.add(chooser,BorderLayout.NORTH);
           jc1.add(done,BorderLayout.SOUTH);
           done.addActionListener(new BackColorDoneButtonAction());
           jc1.setVisible(true);
         }
     }
     class BackColorDoneButtonAction implements ActionListener
     {
         public void actionPerformed(ActionEvent e)
         {
             Color mbcolor=chooser.getColor();
             tx.setBackground(mbcolor);
         }
     }

     //main method
     public static void main(String args[])
      {
          try
            {
             UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
            }
            catch (Exception e)
            {
              e.printStackTrace();
            }
         JFrame jf = new Notepad();
         jf.setTitle("Notepad in Java");
         jf.setExtendedState(6);
         jf.setSize(800,600);
         jf.setVisible(true);
     }
}

3. Compile then run.
Next is the big thing. Test your program. If you got any errors during compilation or debug, be sure to double-check your code with the code provided here.
4. Deploy or build the program
5. Done!