Android Back button Double Exit program

/** * menu, Return key response */@Overridepublic boolean onKeyDown (int keycode, keyevent event) {if (keycode = Keyevent.keycode_back) {EX Itby2click ();//Call the double exit function}return false;} Private Long Exittime = 0;/** * Double exit: Uses the calculated time difference to implement */public void Exitby2click () {if (System.currenttimemillis ()-Exittime) & Gt {Toast.maketext (this, "Press Exit program again", Toast.length_short). Show (); exittime = System.currenttimemillis ();} else { Finish ();}}