Notepad Application (Swing)

[tmotse]

Hi Guys, i developed a notepad application with the the basic fearures: no i need it to only open .txt , .dat , .csv and .sh. i dont know how to do that: Please help guys

Thanks

[PhHein]

How to Use File Choosers (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)

[tmotse]

Here is my code: it opens all extensions i need to limit it to .txt , .dat , .csv and .sh.

package com.notepad;

import java.awt.FileDialog;
/**
 *  * @author tmotseothata
 *
 */
public class Notepad extends Frame {

	/**
	 * @author tmotseothata
	 * 
	 */
	private static final long serialVersionUID = 8462657633177163105L;
	
	// declaring variables
	String filename;
	
	TextArea textarea;
	
	//enabling the data transfer
	//the clipboard class implements the mechanism to transfer data using cut, copy and paste
	Clipboard clip = getToolkit().getSystemClipboard();
	
//constructor Notepad
	/**
	 * 
	 */
	public Notepad() {

		setLayout(new GridLayout(1, 1));
		textarea = new TextArea();

		add(textarea);
        
		
		//creating the MenuBar item
		MenuBar menubar = new MenuBar();
		//file menu
		Menu fl = new Menu("file");
		//other menu items
		MenuItem nw = new MenuItem("New");
		MenuItem op = new MenuItem("Open");
		MenuItem sv = new MenuItem("Save");
		MenuItem ex = new MenuItem("Exit");

		//adding basic menu items
		nw.addActionListener(new New());
		fl.add(nw);

		op.addActionListener(new Open());
		fl.add(op);

		sv.addActionListener(new Save());
		fl.add(sv);

		ex.addActionListener(new Exit());
		fl.add(ex);

		menubar.add(fl);
		
		
        
		//edit menu
		Menu E = new Menu("Edit");
		
		//menu items
		MenuItem cut = new MenuItem("Cut");
		MenuItem copy = new MenuItem("Copy");
		MenuItem paste = new MenuItem("Paste");
		
		//adding basic menu items
		cut.addActionListener(new Cut());
		E.add(cut);
		copy.addActionListener(new Copy());
		E.add(copy);
		paste.addActionListener(new Paste());
		E.add(paste);
		menubar.add(E);
		setMenuBar(menubar);
	
		//creating 
		mylistener mylist = new mylistener();
		addWindowListener(mylist);

	}

	// recieving window events
	//exit window on exit
	public class mylistener extends WindowAdapter {
		public void windowClosing(WindowEvent e) {
			System.exit(0);
		}
	}
	
	// implementation of event listners
	//defines what should be done when a user performs a certain action 

	public class New implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			textarea.setText(" ");
			setTitle(filename);
		}
	}

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

	public class Save implements ActionListener {
	
		//
		public void actionPerformed(ActionEvent e) {
			//display a dialog window from which the user can select a file
			FileDialog fd = new FileDialog(Notepad.this, "Save File",
					FileDialog.SAVE);
			//fd.show(); 
			fd.setVisible(true);
			if (fd.getFile() != null) {
				filename = fd.getDirectory() + fd.getFile();
				setTitle(filename);
				try {
					DataOutputStream d = new DataOutputStream(
							new FileOutputStream(filename));
					String line = textarea.getText();
					BufferedReader br = new BufferedReader(new StringReader(
							line));
					while ((line = br.readLine()) != null) {
						d.writeBytes(line + "\r\n");
						d.close();
					}
				} catch (Exception ex) {
					System.out.println("File not found");
				}
				textarea.requestFocus();
			}
		}
	}

	//implementation of the exit listener: the app terminates on Exit
	public class Exit implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			System.exit(0);
		}
	}
	
//
	public 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");
			textarea.setText(sb.toString());
			d.close();
		} catch (FileNotFoundException fe) {
			System.out.println("File not Found");
		} catch (IOException ioe) {
		}
	}
	
	 public class Cut implements ActionListener
     {
     public void actionPerformed(ActionEvent e)
         {
         String sel = textarea.getSelectedText();
         StringSelection ss = new StringSelection(sel);
         clip.setContents(ss,ss);
         textarea.replaceRange(" ",textarea.getSelectionStart(),textarea.getSelectionEnd());
     }
 }
 
 public class Copy implements ActionListener
     {
     public void actionPerformed(ActionEvent e)
         {
         String sel = textarea.getSelectedText();
         StringSelection clipString = new StringSelection(sel);
         clip.setContents(clipString,clipString);
     }
 }
 
 public class Paste implements ActionListener
     {
     public void actionPerformed(ActionEvent e)
         {
         Transferable cliptran = clip.getContents(Notepad.this);
         try
             {
             String sel = (String) cliptran.getTransferData(DataFlavor.stringFlavor);
             textarea.replaceRange(sel,textarea.getSelectionStart(),textarea.getSelectionEnd());
         }
         catch(Exception exc)
             {
             System.out.println("not string flavour");
         }
     }
 }

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Frame f = new Notepad();
		f.setSize(500, 400);
		f.setVisible(true);
		//f.show();
		

	}

}

[PhHein]

You know I have posted a link to the tutorial. If you're not bothered to read it, there's no way helping you.

[tmotse]

got it Thanks