Netbeans Jinternalframe single instance - netbeans

Question

I have developed an application using net bean,
1) I'm making project in java API 6. I'm using "Net Beans 7.1".
2) I want to use JInternalFrame in my project
3) I made another package and made "JInternalFrame" there. And then call it in my main application window by firing action performed event on "JMenuItem".
4) It works fine but only one problem occurs that is, if i click on "JMenuItem" again and again, new "JInternalFrame" of same instance are opening, How can i stop that?
5) I want that, if I open "JInternalFrame" once and then i again click on "JMenuItem" to open the same "JInternalFrame", it Should do nothing or it shows the window which already opened and minimized
sample code:
<code>
private void empDataActionPerformed(java.awt.event.ActionEvent evt) {
Emps employees = new Emps();
desktop.add(employees);
employees.setVisible(true);
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
employees.setBounds(230, 40, screenSize.width / 2 - 80, screenSize.height / 2 + 105);
}
<code>
please I need help.

Answer 1

Here is may sample code. hope this help.
Menu action to call internal frame in main application where JdesktopPane in it.
private void YourJinternalFrameMenuItemActionPerformed(java.awt.event.ActionEvent evt) {
YourJinternalFrame nw = YourJinternalFrame.getInstance();
nw.pack();
//usefull part for you.. if open shows, if not creates new one
if (nw.isVisible()) {
} else {
desktopPane.add(nw);
nw.setVisible(true);
}
try {
nw.setMaximum(true);
} catch (PropertyVetoException ex) {
Logger.getLogger(MainApplication.class.getName()).log(Level.SEVERE, null, ex);
}
}
put this inside of your YourJinternalFrame
private static YourJinternalFrame myInstance;
public static YourJinternalFrame getInstance() {
if (myInstance == null) {
myInstance = new YourJinternalFrame();
}
return myInstance;