时间加上偏移量于当前时间比较大小 java实现

public static int compareNowDate(String dateStr,int excursion){
SimpleDateFormat formatt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date date = new Date();
Date dt=formatt.parse(dateStr);
Calendar rightNow = Calendar.getInstance();
rightNow.setTime(dt);
rightNow.add(Calendar.DAY_OF_YEAR,excursion);
Date dt1=rightNow.getTime();
if(dt1.getTime()<date.getTime()){
return 1;
}else{
return 0;
}
}
public static void main(String[] args) {
System.out.println(compareNowDate("2017-10-13 14:00:00",7));//10月13日加上7天，然后和当前时间比较
System.out.println(compareNowDate("2017-10-13 14:00:00",-7));//10月13日减去7天，然后和当前时间比较
}