java compare dates

1Date has before and after methods and can be compared to each other as follows:
2
3if(todayDate.after(historyDate) && todayDate.before(futureDate)) {
4    // In between
5}
6For an inclusive comparison:
7
8if(!historyDate.after(todayDate) && !futureDate.before(todayDate)) {
9    /* historyDate <= todayDate <= futureDate */ 
10}
11You could also give Joda-Time a go, but note that:
12
13Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).
14
15Back-ports are available for Java 6 and 7 as well as Android.

1for ( Map.Entry<DayOfWeek , LocalTime> entry : dayToTimeMap.entrySet () ) {
2    DayOfWeek key = entry.getKey ();
3    LocalTime value = entry.getValue ();
4    int comparison = key.compareTo ( today );
5    if ( comparison < 0 ) { // if earlier day…
6        earlier.add ( key );
7    } else if ( comparison == 0 ) { //If same day…
8        if ( value.isBefore ( now ) ) {
9            earlier.add ( key );
10        } else {  // Else same time as now or later than now…
11            later.add ( key );
12        }
13    } else if ( comparison > 0 ) {
14        later.add ( key );
15    } else {
16        throw new RuntimeException ( "Unexpectedly reached IF-ELSE for comparison: " + comparison );
17    }
18}
19

1package javaapplication;
2
3import java.text.*;
4import java.util.Date;
5import java.text.ParseException;
6
7public class date {
8
9    public static void main(String[] args) {
10
11        String startDate = "21-08-2027";
12        String endDate = "21/08/2021";
13
14        try {
15
16            Date dateStart = new SimpleDateFormat("dd-MM-yyyy").parse(startDate);
17
18            Date dateEnd = new SimpleDateFormat("dd/MM/yyyy").parse(endDate);
19
20            if (dateStart.after(dateEnd)) {
21                System.out.println("Start Date is greater than End Date");
22
23            } else if (dateStart.before(dateEnd)) {
24
25                System.out.println("Start Date is less than End Date");
26
27            } else {
28
29                System.out.println("Start Date is Equal to End Date");
30            }
31
32        } catch (ParseException e) {
33            e.printStackTrace();
34        }
35
36    }
37}
38