JButton in java programming?

Question

how to invoke actionlistener of a JButton in java through a command

Answer 1

Just call the listener, if you know which it is.  If not, you can get the list of listeners, as a property, from the button.

Answer 2

assume:

JButton theButton = new JButton();

theButton.addActionListener(yourListen...

to programmatically invoke the listener associated with theButton (in this case yourListener), do this

theButton.doClick();

This will cause theButton to dispatch an ActionEvent to your listener's actionPerformed() method.