Android Continuous Click two times back key exit program

idea 1: Record the last click Time, compared with the time of the click, when two time interval is less than a certain value, exit, otherwise prompt "Press one more time to exit the program , while updating the last click Time

     private long firsttime = 0;     @ Override  public boolean onkeyup (int keycode, keyevent event)  {          // TODO Auto-generated method stub          switch (keycode)           {         case KeyEvent.KEYCODE_BACK:               long secondtime =  system.currenttimemillis ();                 if  (secondtime - firsttime > 2000)  {                                           //if the two-time key time interval is greater than 2 seconds, do not exit                     toast.maketext (this,  "Press again to exit the program",  toast.length_short). Show ();                     firsttime =  secondtime;//Update firsttime                    return true;                 } else {                                                       //Two-time keys less than 2 seconds, exit the app                system.exit (0);                }              break;          }       return super.onkeyup (keycode, event);      }

idea 2: Time delay processing

private int mbackkeypressedtimes = 0;              @Override           public void  onbackpressed ()  {                   if  (mbackkeypressedtimes == 0)  {                            toast.maketext (this,  "Press and Exit program  ",  toast.length_short). Show ();                            mBackKeyPressedTimes = 1;                            new thread () &NBsp {                                    @Override                                    public  Void run ()  {                                            try {                                                     thread.sleep (;            )                                } catch  ( Interruptedexception e)  {                                                     e.printstacktrace ();                                            } finally {                                                     mBackKeyPressedTimes = 0;                                            }                                    }                            }.start ();                           return;                         else{                                   this.activity.finish ();                                }                   }                   super.onbackpressed ();           }

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Android Continuous Click two times back key exit program