摘要：
Car{ Timestamp DateCreated } Map<Timestamp, List<Car>> CarMap = reservePeriodList.stream().collect(groupingBy(Car::getDateCreated)); 阅读全文
摘要：
Timestamp转化为String: SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//定义格式，不显示毫秒 Timestamp now = new Timestamp(System.currentTimeMil 阅读全文