Reshma Bidikar

In this article, I will be covering how to can check if a date is before or after another Date. You can achieve this using the java.util.Date, java.util.Calendar classes or the new Java 8 java.util.LocalDate class.

Using Date class

Using the java.util.Date class, there are two ways to check if a date is before or after another Date. You can either use the before/after method or the compareTo method.

Using Before/After

The java.util.Dateclass has methods before()and after(). You can use these methods to compare two dates. These methods work as follows:

The beforemethod returns true if the date on which is it invoked is before the specified date, otherwise it returns false.
The aftermethod returns true if the date on which is it invoked is after the specified date, otherwise it returns false.

The following code demonstrates this:

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");

Date date1 = simpleDateFormat.parse("2014-08-08");
Date date2 = simpleDateFormat.parse("2018-12-21");

boolean isBefore = date1.before(date2);
boolean isAfter = date1.after(date2);

System.out.println("isBefore:" + isBefore);
System.out.println("isAfter:" + isAfter);

So this code prints the following output:

isBefore:true
isAfter:false

Using CompareTo

The java.util.Dateclass has a method compareTo. You can also use this to compare dates. compareToworks as follows:

Returns 0 if both dates are equal
Returns a value less than 0 if the date on which it is invoked is before the date passed in
Returns a value greater than 0 if the date on which it is invoked is after the date passed in

The following code demonstrates this:

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");

Date date1 = simpleDateFormat.parse("2014-08-08");
Date date2 = simpleDateFormat.parse("2018-12-21");

boolean before = date1.compareTo(date2) < 0 ? true : false;
System.out.println("isBefore:" + before);

boolean after = date1.compareTo(date2) > 0 ? true : false;
System.out.println("isAfter:" + after);

So this code prints the following output:

isBefore:true
isAfter:false

Using Calendar class.

The java.util.Calendaralso has methods before()and after(). You can use these methods to compare two dates.These methods work as follows:

The before method returns true if the Calendar instance on which is it invoked is before the specified Calendar instance, otherwise it returns false.
The after methods returns true if the Calendar instance on which is it invoked is after the specified Calendar instance, otherwise it returns false.

The following code demonstrates this:

Calendar cal1 = new GregorianCalendar(2018, Calendar.AUGUST, 8);
Calendar cal2 = new GregorianCalendar(2014, Calendar.DECEMBER, 21); 

boolean isBefore = cal1.before(cal2);
boolean isAfter = cal1.after(cal2);

System.out.println("isBefore:" + isBefore);
System.out.println("isAfter:" + isAfter);

So this code prints the following output:

isBefore:true
isAfter:false

Just like java.util.Date, there is a compareTo method on the Calendar class. You can also use this method to compare dates.

Using LocalDate

java.util.LocalDate is a new class added by Java 8. It makes Date manipulation/Date arithmetic very easy. It also has methods isBeforeand isAfter. These methods work as follows:

The isBeforemethod returns true if the date on which is it invoked is before the specified date, otherwise it returns false.
The isAftermethod returns true if the date on which is it invoked is after the specified date, otherwise it returns false.

You can use these methods to compare two dates. The following code demonstrates this:

LocalDate date1 = LocalDate.of(2018,Month.AUGUST,8);
LocalDate date2 = LocalDate.of(2014,Month.DECEMBER,21);

boolean isBefore = date1.isBefore(date2);
boolean isAfter = date1.isAfter(date2);

System.out.println("isBefore:"+isBefore);
System.out.println("isAfter:"+isAfter);

So this code prints the following output:

isBefore:false
isAfter:true

Just like java.util.Date, there is a compareTo method on the LocalDate class. You can also use this method to compare dates.

Conclusion

So in this article, we saw how you can check if a date is before/after another date. We saw how to achieve this via the java.util.Date class, java.util.Calendar class and the new Java 8 java.util.LocalDate class.