뒤로 가기 종료

import android.app.Activity;
import android.widget.Toast;

public class BackPressCloseHandler {

    private long backKeyPressedTime = 0;
    private Toast toast;

    private Activity activity;

    public BackPressCloseHandler(Activity context) {
         this.activity = context;
    }

    public void onBackPressed() {
        if(System.currentTimeMillis() > backKeyPressedTime + 3000) {
            backKeyPressedTime = System.currentTimeMillis();
            showGuide();
            return;
        }
        if(System.currentTimeMillis() <= backKeyPressedTime + 3000) {
            activity.finishAffinity();
            activity.finish();
            android.os.Process.killProcess(android.os.Process.myPid());
            toast.cancel();
        }
    }

    private void showGuide() {
        toast = Toast.makeText(activity,"뒤로가기 버튼을 한 번 더 누르시면 종료됩니다", Toast.LENGTH_SHORT);
        toast.show();
    }
}