我写了一些代码来检查两个日期，开始日期和结束日期。如果结束日期在开始日期之前，则会提示结束日期在开始日期之前。
我还想添加一个检查，看看开始日期是否在今天之前（今天是用户使用应用程序的那天）我该怎么做？ （下面的日期检查代码，如果有任何影响的话，所有这些都是为Android编写的）
if (startYear > endYear) {
fill = fill + 1;
message = message + "End Date is Before Start Date" + "\n";
} else if (startMonth > endMonth && startYear >= endYear) {
fill = fill + 1;
message = message + "End Date is Before Start Date" + "\n";
} else if (startDay > endDay && startMonth >= endMonth && startYear >= endYear) {
fill = fill + 1;
message = message + "End Date is Before Start Date" + "\n";
}
答案 0 :(得分：107)
DateUtils.isSameDay(date1,date2);
DateUtils.isSameDay(calender1,calender2);
DateUtils.isToday(date1);
有关详情，请参阅此文DateUtils Java
答案 1 :(得分：41)
这有帮助吗？
Calendar c = Calendar.getInstance();
// set the calendar to start of today
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
// and get that as a Date
Date today = c.getTime();
// or as a timestamp in milliseconds
long todayInMillis = c.getTimeInMillis();
// user-specified date which you are testing
// let's say the components come from a form or something
int year = 2011;
int month = 5;
int dayOfMonth = 20;
// reuse the calendar to set user specified date
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, month);
c.set(Calendar.DAY_OF_MONTH, dayOfMonth);
// and get that as a Date
Date dateSpecified = c.getTime();
// test your condition
if (dateSpecified.before(today)) {
System.err.println("Date specified [" + dateSpecified + "] is before today [" + today + "]");
} else {
System.err.println("Date specified [" + dateSpecified + "] is NOT before today [" + today + "]");
}
答案 2 :(得分：7)
Android已经有了专门的课程。查看DateUtils.isToday(long when)
答案 3 :(得分：5)
使用Joda Time这可以简化为：
DateMidnight startDate = new DateMidnight(startYear, startMonth, startDay);
if (startDate.isBeforeNow())
{
// startDate is before now
// do something...
}
答案 4 :(得分：5)
其他答案忽略了time zone的关键问题。
其他答案使用过时的类。
与最早版本的Java捆绑在一起的旧日期时间类设计糟糕，令人困惑且麻烦。避免使用java.util.Date/.Calendar和相关的类。
LocalDate 对于仅限日期的值，没有时间和没有时区，请使用LocalDate类。
LocalDate start = LocalDate.of( 2016 , 1 , 1 );
LocalDate stop = start.plusWeeks( 1 );
请注意，虽然LocalDate不存储时区，但确定日期（例如“今天”）需要时区。对于任何特定时刻，日期可能因时区而异。例如，巴黎的新日早些时候比蒙特利尔早。巴黎午夜过后的一刻仍然在蒙特利尔的“昨天”。
如果您只拥有offset-from-UTC，请使用ZoneOffset。如果您有完整时区（大陆/地区），请使用ZoneId。如果您想要UTC，请使用方便的常量ZoneOffset.UTC。
ZoneId zoneId = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( zoneId );
使用isEqual，isBefore和isAfter方法进行比较很简单。
boolean invalidInterval = stop.isBefore( start );
我们可以查看今天是否包含在此日期范围内。在我这里显示的逻辑中，我使用半开放式方法，其中开头是包含，而结尾是独占。这种方法在日期工作中很常见。因此，例如，一周从周一开始，但不包括下周一。
// Is today equal or after start (not before) AND today is before stop.
boolean intervalContainsToday = ( ! today.isBefore( start ) ) && today.isBefore( stop ) ) ;
Interval 如果需要花费大量时间，请考虑将ThreeTen-Extra库添加到项目中。该库扩展了java.time框架，并且是可能添加到java.time的试验场。
ThreeTen-Extra包含Interval课程，其中包含abuts，contains，encloses，overlaps等便捷方法。
java.time框架内置于Java 8及更高版本中。这些类取代了麻烦的旧legacy日期时间类，例如java.util.Date，Calendar和＆amp; SimpleDateFormat
现在位于Joda-Time的maintenance mode项目建议迁移到java.time类。
要了解详情，请参阅Oracle Tutorial。并搜索Stack Overflow以获取许多示例和解释。规范是JSR 310。
您可以直接与数据库交换 java.time 对象。使用符合JDBC driver或更高版本的JDBC 4.2。不需要字符串，不需要java.sql.*类。
从哪里获取java.time类？
答案 5 :(得分：5)
public static boolean isToday(Date date){
Calendar today = Calendar.getInstance();
Calendar specifiedDate = Calendar.getInstance();
specifiedDate.setTime(date);
return today.get(Calendar.DAY_OF_MONTH) == specifiedDate.get(Calendar.DAY_OF_MONTH)
&& today.get(Calendar.MONTH) == specifiedDate.get(Calendar.MONTH)
&& today.get(Calendar.YEAR) == specifiedDate.get(Calendar.YEAR);
}
答案 6 :(得分：4)
检查日期是否是今天的日期，或者不检查日期，而不是时间，因此请将时间00:00:00并使用下面的代码
Calendar c = Calendar.getInstance();
// set the calendar to start of today
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
Date today = c.getTime();
// or as a timestamp in milliseconds
long todayInMillis = c.getTimeInMillis();
int dayOfMonth = 24;
int month = 4;
int year =2013;
// reuse the calendar to set user specified date
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, month - 1);
c.set(Calendar.DAY_OF_MONTH, dayOfMonth);
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
// and get that as a Date
Date dateSpecified = c.getTime();
// test your condition
if (dateSpecified.before(today)) {
Log.v(" date is previou")
} else if (dateSpecified.equal(today)) {
Log.v(" date is today ")
}
else if (dateSpecified.after(today)) {
Log.v(" date is future date ")
}
希望它会有所帮助....
答案 7 :(得分：2)
boolean isBeforeToday(Date d) {
Date today = new Date();
today.setHours(0);
today.setMinutes(0);
today.setSeconds(0);
return d.before(today);
}
答案 8 :(得分：1)
我假设您使用整数代表您的年，月和日？如果要保持一致，请使用Date方法。
Calendar cal = new Calendar();
int currentYear, currentMonth, currentDay;
currentYear = cal.get(Calendar.YEAR);
currentMonth = cal.get(Calendar.MONTH);
currentDay = cal.get(Calendar.DAY_OF_WEEK);
if(startYear < currentYear)
{
message = message + "Start Date is Before Today" + "\n";
}
else if(startMonth < currentMonth && startYear <= currentYear)
{
message = message + "Start Date is Before Today" + "\n";
}
else if(startDay < currentDay && startMonth <= currentMonth && startYear <= currentYear)
{
message = message + "Start Date is Before Today" + "\n";
}
答案 9 :(得分：1)
执行此操作的另一种方法：
public class TimeUtils {
/**
* @param timestamp
* @return
*/
public static boolean isToday(long timestamp) {
Calendar now = Calendar.getInstance();
Calendar timeToCheck = Calendar.getInstance();
timeToCheck.setTimeInMillis(timestamp);
return (now.get(Calendar.YEAR) == timeToCheck.get(Calendar.YEAR)
&& now.get(Calendar.DAY_OF_YEAR) == timeToCheck.get(Calendar.DAY_OF_YEAR));
}
}
答案 10 :(得分：0)
试试这个：
public static boolean isToday(Date date)
{
return org.apache.commons.lang3.time.DateUtils.isSameDay(Calendar.getInstance().getTime(),date);
}
答案 11 :(得分：0)
public static boolean itIsToday(long date){
boolean result = false;
try{
Calendar calendarData = Calendar.getInstance();
calendarData.setTimeInMillis(date);
calendarData.set(Calendar.HOUR_OF_DAY, 0);
calendarData.set(Calendar.MINUTE, 0);
calendarData.set(Calendar.SECOND, 0);
calendarData.set(Calendar.MILLISECOND, 0);
Calendar calendarToday = Calendar.getInstance();
calendarToday.setTimeInMillis(System.currentTimeMillis());
calendarToday.set(Calendar.HOUR_OF_DAY, 0);
calendarToday.set(Calendar.MINUTE, 0);
calendarToday.set(Calendar.SECOND, 0);
calendarToday.set(Calendar.MILLISECOND, 0);
if(calendarToday.getTimeInMillis() == calendarData.getTimeInMillis()) {
result = true;
}
}catch (Exception exception){
Log.e(TAG, exception);
}
return result;
}