問題描述

如題，根據時間戳怎么判斷是不是昨天呢?

問題解答

JDK 內置方式

public static boolean isYesterday(long timestamp) { Calendar c = Calendar.getInstance(); clearCalendar(c, Calendar.HOUR_OF_DAY, Calendar.MINUTE, Calendar.SECOND, Calendar.MILLISECOND); c.add(Calendar.DAY_OF_MONTH, -1); long firstOfDay = c.getTimeInMillis(); // 昨天最早時間 c.setTimeInMillis(timestamp); clearCalendar(c, Calendar.HOUR_OF_DAY, Calendar.MINUTE, Calendar.SECOND, Calendar.MILLISECOND); // 指定時間戳當天最早時間 return firstOfDay == c.getTimeInMillis();}private static void clearCalendar(Calendar c, int... fields) { for (int f : fields) {c.set(f, 0); }}回答2：

( ( timestamp - System.currentTimeMillis() ) / (3600 * 24) ) == -1回答3：

public boolean isYesterday(long time) { boolean isYesterday = false; Date date; try {SimpleDateFormat sdf = new SimpleDateFormat('yyyy-MM-dd');date = sdf.parse(sdf.format(new Date()));if (time < date.getTime() && time > (date.getTime() - 24*60*60*1000)) { isYesterday = true;} } catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace(); } return isYesterday;}