Android getRunActivityClassName (현재 실행중인 액티비티의 패키지명 가져오기)

public static String getRunActivityClassName(Context context) {
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<ActivityManager.RunningTaskInfo> taskInfo = activityManager.getRunningTasks(1);
    ComponentName topActivity = taskInfo.get(0).topActivity;
    String className = topActivity.getClassName();

    return className;
}