1.获得当天15:30的时间
Calendar cal = Calendar.getInstance(); cal.set(Calendar.HOUR_OF_DAY, 15); cal.set(Calendar.MINUTE, 30); cal.set(Calendar.SECOND, 00); Date todayHalfToFour = cal.getTime();
2.获取前天或者昨天15:30这个时间Date、判断一个Date是否早于另一个Date
if (now.before(todayHalfToFour)) { beginDate = new Date(todayHalfToFour.getTime() - 2 * 24 * 3600 * 1000); endDate = now; } else { beginDate = new Date(todayHalfToFour.getTime() - 24 * 3600 * 1000); endDate = now; }
3.从map的entry中获取到Date类型的value,其实是Object对象,可以直接转为Date类型。指定时间格式SimpleDateFormat。
sdf.format()后得到的是String。
Date updateTime =(Date) entry.getValue().get("updateTime"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm"); map.put("updateTime", sdf.format(updateTime));