Question

I am trying to create a Key Listener in java however when I try

KeyListener listener = new KeyListener(); 

Netbeans is telling me that KeyListener is abstract;cannot be instantiated. I know that I am missing some other piece of this key listener, but since this is my first time using a key listener i am unsure of what else i need. Why is it telling me this?

Thanks,

Tomek

Answer 1

KeyListener is an interface – it has to be implemented by something. So you could do:

KeyListener listener = new SomeKeyListenerImplementation(); 

but you can’t instantiate it directly. You could use an anonymous inner class:

KeyListener listener = new KeyListener() {     public void keyPressed(KeyEvent e) { /* ... */ }      public void keyReleased(KeyEvent e) { /* ... */ }      public void keyTyped(KeyEvent e) { /* ... */ } }; 

It depends on what you want to do, basically.