Notepad in Java with source code

Notepad in Java with source code: We can develop Notepad in java with the help of AWT/Swing with event handling. Let's see the code of creating Notepad in java.
import java.io.*;
import java.util.Date;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

/************************************/
class FileOperation
{
Notepad npd;

boolean saved;
boolean newFileFlag;
String fileName;
String applicationTitle="Notepad - JavaTpoint";

File fileRef;
JFileChooser chooser;
/////////////////////////////
boolean isSave(){return saved;}
void setSave(boolean saved){this.saved=saved;}
String getFileName(){return new String(fileName);}
void setFileName(String fileName){this.fileName=new String(fileName);}
/////////////////////////
FileOperation(Notepad npd)
{
this.npd=npd;

saved=true;
newFileFlag=true;
fileName=new String("Untitled");
fileRef=new File(fileName);
this.npd.f.setTitle(fileName+" - "+applicationTitle);

chooser=new JFileChooser();
chooser.addChoosableFileFilter(new MyFileFilter(".java","Java Source Files(*.java)"));
chooser.addChoosableFileFilter(new MyFileFilter(".txt","Text Files(*.txt)"));
chooser.setCurrentDirectory(new File("."));

}
//////////////////////////////////////

boolean saveFile(File temp)
{
FileWriter fout=null;
try
{
fout=new FileWriter(temp);
fout.write(npd.ta.getText());
}
catch(IOException ioe){updateStatus(temp,false);return false;}
finally
{try{fout.close();}catch(IOException excp){}}
updateStatus(temp,true);
return true;
}
////////////////////////
boolean saveThisFile()
{

if(!newFileFlag)
	{return saveFile(fileRef);}

return saveAsFile();
}
////////////////////////////////////
boolean saveAsFile()
{
File temp=null;
chooser.setDialogTitle("Save As...");
chooser.setApproveButtonText("Save Now"); 
chooser.setApproveButtonMnemonic(KeyEvent.VK_S);
chooser.setApproveButtonToolTipText("Click me to save!");

do
{
if(chooser.showSaveDialog(this.npd.f)!=JFileChooser.APPROVE_OPTION)
	return false;
temp=chooser.getSelectedFile();
if(!temp.exists()) break;
if(   JOptionPane.showConfirmDialog(
	this.npd.f,"<html>"+temp.getPath()+" already exists.<br>Do you want to replace it?<html>",
	"Save As",JOptionPane.YES_NO_OPTION
				)==JOptionPane.YES_OPTION)
	break;
}while(true);


return saveFile(temp);
}

////////////////////////
boolean openFile(File temp)
{
FileInputStream fin=null;
BufferedReader din=null;

try
{
fin=new FileInputStream(temp);
din=new BufferedReader(new InputStreamReader(fin));
String str=" ";
while(str!=null)
{
str=din.readLine();
if(str==null)
break;
this.npd.ta.append(str+"\n");
}

}
catch(IOException ioe){updateStatus(temp,false);return false;}
finally
{try{din.close();fin.close();}catch(IOException excp){}}
updateStatus(temp,true);
this.npd.ta.setCaretPosition(0);
return true;
}
///////////////////////
void openFile()
{
if(!confirmSave()) return;
chooser.setDialogTitle("Open File...");
chooser.setApproveButtonText("Open this"); 
chooser.setApproveButtonMnemonic(KeyEvent.VK_O);
chooser.setApproveButtonToolTipText("Click me to open the selected file.!");

File temp=null;
do
{
if(chooser.showOpenDialog(this.npd.f)!=JFileChooser.APPROVE_OPTION)
	return;
temp=chooser.getSelectedFile();

if(temp.exists())	break;

JOptionPane.showMessageDialog(this.npd.f,
	"<html>"+temp.getName()+"<br>file not found.<br>"+
	"Please verify the correct file name was given.<html>",
	"Open",	JOptionPane.INFORMATION_MESSAGE);

} while(true);

this.npd.ta.setText("");

if(!openFile(temp))
	{
	fileName="Untitled"; saved=true; 
	this.npd.f.setTitle(fileName+" - "+applicationTitle);
	}
if(!temp.canWrite())
	newFileFlag=true;

}
////////////////////////
void updateStatus(File temp,boolean saved)
{
if(saved)
{
this.saved=true;
fileName=new String(temp.getName());
if(!temp.canWrite())
	{fileName+="(Read only)"; newFileFlag=true;}
fileRef=temp;
npd.f.setTitle(fileName + " - "+applicationTitle);
npd.statusBar.setText("File : "+temp.getPath()+" saved/opened successfully.");
newFileFlag=false;
}
else
{
npd.statusBar.setText("Failed to save/open : "+temp.getPath());
}
}
///////////////////////
boolean confirmSave()
{
String strMsg="<html>The text in the "+fileName+" file has been changed.<br>"+
	"Do you want to save the changes?<html>";
if(!saved)
{
int x=JOptionPane.showConfirmDialog(this.npd.f,strMsg,applicationTitle,
JOptionPane.YES_NO_CANCEL_OPTION);

if(x==JOptionPane.CANCEL_OPTION) return false;
if(x==JOptionPane.YES_OPTION && !saveAsFile()) return false;
}
return true;
}
///////////////////////////////////////
void newFile()
{
if(!confirmSave()) return;

this.npd.ta.setText("");
fileName=new String("Untitled");
fileRef=new File(fileName);
saved=true;
newFileFlag=true;
this.npd.f.setTitle(fileName+" - "+applicationTitle);
}
//////////////////////////////////////
}// end defination of class FileOperation
/************************************/
public class Notepad  implements ActionListener, MenuConstants
{

JFrame f;
JTextArea ta;
JLabel statusBar;

private String fileName="Untitled";
private boolean saved=true;
String applicationName="Javapad";

String searchString, replaceString;
int lastSearchIndex;

FileOperation fileHandler;
FontChooser fontDialog=null;
FindDialog findReplaceDialog=null; 
JColorChooser bcolorChooser=null;
JColorChooser fcolorChooser=null;
JDialog backgroundDialog=null;
JDialog foregroundDialog=null;
JMenuItem cutItem,copyItem, deleteItem, findItem, findNextItem,
replaceItem, gotoItem, selectAllItem;
/****************************/
Notepad()
{
f=new JFrame(fileName+" - "+applicationName);
ta=new JTextArea(30,60);
statusBar=new JLabel("||       Ln 1, Col 1  ",JLabel.RIGHT);
f.add(new JScrollPane(ta),BorderLayout.CENTER);
f.add(statusBar,BorderLayout.SOUTH);
f.add(new JLabel("  "),BorderLayout.EAST);
f.add(new JLabel("  "),BorderLayout.WEST);
createMenuBar(f);
//f.setSize(350,350);
f.pack();
f.setLocation(100,50);
f.setVisible(true);
f.setLocation(150,50);
f.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

fileHandler=new FileOperation(this);

/////////////////////

ta.addCaretListener(
new CaretListener()
{
public void caretUpdate(CaretEvent e)
{
int lineNumber=0, column=0, pos=0;

try
{
pos=ta.getCaretPosition();
lineNumber=ta.getLineOfOffset(pos);
column=pos-ta.getLineStartOffset(lineNumber);
}catch(Exception excp){}
if(ta.getText().length()==0){lineNumber=0; column=0;}
statusBar.setText("||       Ln "+(lineNumber+1)+", Col "+(column+1));
}
});
//////////////////
DocumentListener myListener = new DocumentListener()
{
public void changedUpdate(DocumentEvent e){fileHandler.saved=false;}
public void removeUpdate(DocumentEvent e){fileHandler.saved=false;}
public void insertUpdate(DocumentEvent e){fileHandler.saved=false;}
};
ta.getDocument().addDocumentListener(myListener);
/////////
WindowListener frameClose=new WindowAdapter()
{
public void windowClosing(WindowEvent we)
{
if(fileHandler.confirmSave())System.exit(0);
}
};
f.addWindowListener(frameClose);
//////////////////
/*
ta.append("Hello dear hello hi");
ta.append("\nwho are u dear mister hello");
ta.append("\nhello bye hel");
ta.append("\nHello");
ta.append("\nMiss u mister hello hell");
fileHandler.saved=true;
*/
}
////////////////////////////////////
void goTo()
{
int lineNumber=0;
try
{
lineNumber=ta.getLineOfOffset(ta.getCaretPosition())+1;
String tempStr=JOptionPane.showInputDialog(f,"Enter Line Number:",""+lineNumber);
if(tempStr==null)
	{return;}
lineNumber=Integer.parseInt(tempStr);
ta.setCaretPosition(ta.getLineStartOffset(lineNumber-1));
}catch(Exception e){}
}
///////////////////////////////////
public void actionPerformed(ActionEvent ev)
{
String cmdText=ev.getActionCommand();
////////////////////////////////////
if(cmdText.equals(fileNew))
	fileHandler.newFile();
else if(cmdText.equals(fileOpen))
	fileHandler.openFile();
////////////////////////////////////
else if(cmdText.equals(fileSave))
	fileHandler.saveThisFile();
////////////////////////////////////
else if(cmdText.equals(fileSaveAs))
	fileHandler.saveAsFile();
////////////////////////////////////
else if(cmdText.equals(fileExit))
	{if(fileHandler.confirmSave())System.exit(0);}
////////////////////////////////////
else if(cmdText.equals(filePrint))
JOptionPane.showMessageDialog(
	Notepad.this.f,
	"Get ur printer repaired first! It seems u dont have one!",
	"Bad Printer",
	JOptionPane.INFORMATION_MESSAGE
	);
////////////////////////////////////
else if(cmdText.equals(editCut))
	ta.cut();
////////////////////////////////////
else if(cmdText.equals(editCopy))
	ta.copy();
////////////////////////////////////
else if(cmdText.equals(editPaste))
	ta.paste();
////////////////////////////////////
else if(cmdText.equals(editDelete))
	ta.replaceSelection("");
////////////////////////////////////
else if(cmdText.equals(editFind))
{
if(Notepad.this.ta.getText().length()==0)
	return;	// text box have no text
if(findReplaceDialog==null)
	findReplaceDialog=new FindDialog(Notepad.this.ta);
findReplaceDialog.showDialog(Notepad.this.f,true);//find
}
////////////////////////////////////
else if(cmdText.equals(editFindNext))
{
if(Notepad.this.ta.getText().length()==0)
	return;	// text box have no text

if(findReplaceDialog==null)
	statusBar.setText("Use Find option of Edit Menu first !!!!");
else
	findReplaceDialog.findNextWithSelection();
}
////////////////////////////////////
else if(cmdText.equals(editReplace))
{
if(Notepad.this.ta.getText().length()==0)
	return;	// text box have no text

if(findReplaceDialog==null)
	findReplaceDialog=new FindDialog(Notepad.this.ta);
findReplaceDialog.showDialog(Notepad.this.f,false);//replace
}
////////////////////////////////////
else if(cmdText.equals(editGoTo))
{
if(Notepad.this.ta.getText().length()==0)
	return;	// text box have no text
goTo();
}
////////////////////////////////////
else if(cmdText.equals(editSelectAll))
	ta.selectAll();
////////////////////////////////////
else if(cmdText.equals(editTimeDate))
	ta.insert(new Date().toString(),ta.getSelectionStart());
////////////////////////////////////
else if(cmdText.equals(formatWordWrap))
{
JCheckBoxMenuItem temp=(JCheckBoxMenuItem)ev.getSource();
ta.setLineWrap(temp.isSelected());
}
////////////////////////////////////
else if(cmdText.equals(formatFont))
{
if(fontDialog==null)
	fontDialog=new FontChooser(ta.getFont());

if(fontDialog.showDialog(Notepad.this.f,"Choose a font"))
	Notepad.this.ta.setFont(fontDialog.createFont());
}
////////////////////////////////////
else if(cmdText.equals(formatForeground))
	showForegroundColorDialog();
////////////////////////////////////
else if(cmdText.equals(formatBackground))
	showBackgroundColorDialog();
////////////////////////////////////

else if(cmdText.equals(viewStatusBar))
{
JCheckBoxMenuItem temp=(JCheckBoxMenuItem)ev.getSource();
statusBar.setVisible(temp.isSelected());
}
////////////////////////////////////
else if(cmdText.equals(helpAboutNotepad))
{
JOptionPane.showMessageDialog(Notepad.this.f,aboutText,"Dedicated 2 u!",
JOptionPane.INFORMATION_MESSAGE);
}
else
	statusBar.setText("This "+cmdText+" command is yet to be implemented");
}//action Performed
////////////////////////////////////
void showBackgroundColorDialog()
{
if(bcolorChooser==null)
	bcolorChooser=new JColorChooser();
if(backgroundDialog==null)
	backgroundDialog=JColorChooser.createDialog
		(Notepad.this.f,
		formatBackground,
		false,
		bcolorChooser,
		new ActionListener()
		{public void actionPerformed(ActionEvent evvv){
			Notepad.this.ta.setBackground(bcolorChooser.getColor());}},
		null);		

backgroundDialog.setVisible(true);
}
////////////////////////////////////
void showForegroundColorDialog()
{
if(fcolorChooser==null)
	fcolorChooser=new JColorChooser();
if(foregroundDialog==null)
	foregroundDialog=JColorChooser.createDialog
		(Notepad.this.f,
		formatForeground,
		false,
		fcolorChooser,
		new ActionListener()
		{public void actionPerformed(ActionEvent evvv){
			Notepad.this.ta.setForeground(fcolorChooser.getColor());}},
		null);		

foregroundDialog.setVisible(true);
}

///////////////////////////////////
JMenuItem createMenuItem(String s, int key,JMenu toMenu,ActionListener al)
{
JMenuItem temp=new JMenuItem(s,key);
temp.addActionListener(al);
toMenu.add(temp);

return temp;
}
////////////////////////////////////
JMenuItem createMenuItem(String s, int key,JMenu toMenu,int aclKey,ActionListener al)
{
JMenuItem temp=new JMenuItem(s,key);
temp.addActionListener(al);
temp.setAccelerator(KeyStroke.getKeyStroke(aclKey,ActionEvent.CTRL_MASK));
toMenu.add(temp);

return temp;
}
////////////////////////////////////
JCheckBoxMenuItem createCheckBoxMenuItem(String s,
 int key,JMenu toMenu,ActionListener al)
{
JCheckBoxMenuItem temp=new JCheckBoxMenuItem(s);
temp.setMnemonic(key);
temp.addActionListener(al);
temp.setSelected(false);
toMenu.add(temp);

return temp;
}
////////////////////////////////////
JMenu createMenu(String s,int key,JMenuBar toMenuBar)
{
JMenu temp=new JMenu(s);
temp.setMnemonic(key);
toMenuBar.add(temp);
return temp;
}
/*********************************/
void createMenuBar(JFrame f)
{
JMenuBar mb=new JMenuBar();
JMenuItem temp;

JMenu fileMenu=createMenu(fileText,KeyEvent.VK_F,mb);
JMenu editMenu=createMenu(editText,KeyEvent.VK_E,mb);
JMenu formatMenu=createMenu(formatText,KeyEvent.VK_O,mb);
JMenu viewMenu=createMenu(viewText,KeyEvent.VK_V,mb);
JMenu helpMenu=createMenu(helpText,KeyEvent.VK_H,mb);

createMenuItem(fileNew,KeyEvent.VK_N,fileMenu,KeyEvent.VK_N,this);
createMenuItem(fileOpen,KeyEvent.VK_O,fileMenu,KeyEvent.VK_O,this);
createMenuItem(fileSave,KeyEvent.VK_S,fileMenu,KeyEvent.VK_S,this);
createMenuItem(fileSaveAs,KeyEvent.VK_A,fileMenu,this);
fileMenu.addSeparator();
temp=createMenuItem(filePageSetup,KeyEvent.VK_U,fileMenu,this);
temp.setEnabled(false);
createMenuItem(filePrint,KeyEvent.VK_P,fileMenu,KeyEvent.VK_P,this);
fileMenu.addSeparator();
createMenuItem(fileExit,KeyEvent.VK_X,fileMenu,this);

temp=createMenuItem(editUndo,KeyEvent.VK_U,editMenu,KeyEvent.VK_Z,this);
temp.setEnabled(false);
editMenu.addSeparator();
cutItem=createMenuItem(editCut,KeyEvent.VK_T,editMenu,KeyEvent.VK_X,this);
copyItem=createMenuItem(editCopy,KeyEvent.VK_C,editMenu,KeyEvent.VK_C,this);
createMenuItem(editPaste,KeyEvent.VK_P,editMenu,KeyEvent.VK_V,this);
deleteItem=createMenuItem(editDelete,KeyEvent.VK_L,editMenu,this);
deleteItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_DELETE,0));
editMenu.addSeparator();
findItem=createMenuItem(editFind,KeyEvent.VK_F,editMenu,KeyEvent.VK_F,this);
findNextItem=createMenuItem(editFindNext,KeyEvent.VK_N,editMenu,this);
findNextItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F3,0));
replaceItem=createMenuItem(editReplace,KeyEvent.VK_R,editMenu,KeyEvent.VK_H,this);
gotoItem=createMenuItem(editGoTo,KeyEvent.VK_G,editMenu,KeyEvent.VK_G,this);
editMenu.addSeparator();
selectAllItem=createMenuItem(editSelectAll,KeyEvent.VK_A,editMenu,KeyEvent.VK_A,this);
createMenuItem(editTimeDate,KeyEvent.VK_D,editMenu,this)
.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F5,0));

createCheckBoxMenuItem(formatWordWrap,KeyEvent.VK_W,formatMenu,this);

createMenuItem(formatFont,KeyEvent.VK_F,formatMenu,this);
formatMenu.addSeparator();
createMenuItem(formatForeground,KeyEvent.VK_T,formatMenu,this);
createMenuItem(formatBackground,KeyEvent.VK_P,formatMenu,this);

createCheckBoxMenuItem(viewStatusBar,KeyEvent.VK_S,viewMenu,this).setSelected(true);
/************For Look and Feel***/
LookAndFeelMenu.createLookAndFeelMenuItem(viewMenu,this.f);


temp=createMenuItem(helpHelpTopic,KeyEvent.VK_H,helpMenu,this);
temp.setEnabled(false);
helpMenu.addSeparator();
createMenuItem(helpAboutNotepad,KeyEvent.VK_A,helpMenu,this);

MenuListener editMenuListener=new MenuListener()
{
   public void menuSelected(MenuEvent evvvv)
	{
	if(Notepad.this.ta.getText().length()==0)
	{
	findItem.setEnabled(false);
	findNextItem.setEnabled(false);
	replaceItem.setEnabled(false);
	selectAllItem.setEnabled(false);
	gotoItem.setEnabled(false);
	}
	else
	{
	findItem.setEnabled(true);
	findNextItem.setEnabled(true);
	replaceItem.setEnabled(true);
	selectAllItem.setEnabled(true);
	gotoItem.setEnabled(true);
	}
	if(Notepad.this.ta.getSelectionStart()==ta.getSelectionEnd())
	{
	cutItem.setEnabled(false);
	copyItem.setEnabled(false);
	deleteItem.setEnabled(false);
	}
	else
	{
	cutItem.setEnabled(true);
	copyItem.setEnabled(true);
	deleteItem.setEnabled(true);
	}
	}
   public void menuDeselected(MenuEvent evvvv){}
   public void menuCanceled(MenuEvent evvvv){}
};
editMenu.addMenuListener(editMenuListener);
f.setJMenuBar(mb);
}
/*************Constructor**************/
////////////////////////////////////
public static void main(String[] s)
{
new Notepad();
}
}
/**************************************/
//public
interface MenuConstants
{
final String fileText="File";
final String editText="Edit";
final String formatText="Format";
final String viewText="View";
final String helpText="Help";

final String fileNew="New";
final String fileOpen="Open...";
final String fileSave="Save";
final String fileSaveAs="Save As...";
final String filePageSetup="Page Setup...";
final String filePrint="Print";
final String fileExit="Exit";

final String editUndo="Undo";
final String editCut="Cut";
final String editCopy="Copy";
final String editPaste="Paste";
final String editDelete="Delete";
final String editFind="Find...";
final String editFindNext="Find Next";
final String editReplace="Replace";
final String editGoTo="Go To...";
final String editSelectAll="Select All";
final String editTimeDate="Time/Date";

final String formatWordWrap="Word Wrap";
final String formatFont="Font...";
final String formatForeground="Set Text color...";
final String formatBackground="Set Pad color...";

final String viewStatusBar="Status Bar";

final String helpHelpTopic="Help Topic";
final String helpAboutNotepad="About Javapad";

final String aboutText="Your Javapad";
}
download this example
Next TopicCalculator in Java
← prev next →
For Videos Join Our Youtube Channel: Join Now
Help Others, Please Share

Learn Latest Tutorials

SoapUI
RPA
Manual T.
Cucumber
Appium
PostgreSQL
Solr
MongoDB
Gimp
Verilog
Teradata
PhoneGap
Preparation

Aptitude
Reasoning
Verbal A.
Interview
Company
Trending Technologies

AWS
Selenium
Cloud
Hadoop
ReactJS
D. Science
Angular 7
Blockchain
Git
DevOps
B.Tech / MCA

DBMS
DAA
C. Network
Compiler D.
COA
D. Math.
E. Hacking
C. Graphics
Software E.
Web Tech.
Cyber Sec.
Automata
C++
Java
.Net
Python
Programs
Control S.
Data Mining
Javatpoint Services

JavaTpoint offers too many high quality services. Mail us on hr@javatpoint.com, to get more information about given services.
Website Designing
Website Development
Java Development
PHP Development
WordPress
Graphic Designing
Logo
Digital Marketing
On Page and Off Page SEO
PPC
Content Development
Corporate Training
Classroom and Online Training
Data Entry
Training For College Campus

JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Please mail your requirement at hr@javatpoint.com.
Duration: 1 week to 2 week
^{Like/Subscribe us for latest updates or newsletter}
Java Swing

Java Swing Apps

LayoutManagers
