java - Omit empty function signiture on listener creation -

sorry newbie question - possible omit empty function signatures when implementing mouselistener class (or every other inner class)?
code shrink few lines?

    jbutton btnexit = new jbutton("exit");     btnexit.addmouselistener(new mouselistener() {         @override public void mousereleased(mouseevent arg0) {}         @override public void mousepressed(mouseevent arg0) {system.exit(0);}         @override public void mouseexited(mouseevent arg0) {}         @override public void mouseentered(mouseevent arg0) {}         @override public void mouseclicked(mouseevent arg0) {}     }); 

use mouseadapter , override function required

btnexit.addmouselistener(new mouseadapter() {      @override public void mousepressed(mouseevent arg0) {system.exit(0);}  });