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How to compare dates in Java

编辑教程

Few examples show you how to compare two dates in Java. Updated with Java 8 examples.

1. Date.compareTo()

A classic method to compare two java.util.Date in Java.

  1. Return value is 0 if both dates are equal.
  2. Return value is greater than 0 , if Date is after the date argument.
  3. Return value is less than 0, if Date is before the date argument.

TestDate.java

package com.mkyong.date;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class TestDate {

    public static void main(String[] args) throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date date1 = sdf.parse("2009-12-31");
        Date date2 = sdf.parse("2010-01-31");

        System.out.println("date1 : " + sdf.format(date1));
        System.out.println("date2 : " + sdf.format(date2));

        if (date1.compareTo(date2) > 0) {
            System.out.println("Date1 is after Date2");
        } else if (date1.compareTo(date2) < 0) {
            System.out.println("Date1 is before Date2");
        } else if (date1.compareTo(date2) == 0) {
            System.out.println("Date1 is equal to Date2");
        } else {
            System.out.println("How to get here?");
        }

    }

}

Output

date1 : 2009-12-31
date2 : 2010-01-31
Date1 is before Date2

2. Date.before(), Date.after() and Date.equals()

A more user friendly method to compare two java.util.Date

TestDate2.java

package com.mkyong.date;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class TestDate2 {

    public static void main(String[] args) throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date date1 = sdf.parse("2009-12-31");
        Date date2 = sdf.parse("2010-01-31");

        System.out.println("date1 : " + sdf.format(date1));
        System.out.println("date2 : " + sdf.format(date2));

        if (date1.after(date2)) {
            System.out.println("Date1 is after Date2");
        }

        if (date1.before(date2)) {
            System.out.println("Date1 is before Date2");
        }

        if (date1.equals(date2)) {
            System.out.println("Date1 is equal Date2");
        }

    }

}

Output

date1 : 2009-12-31
date2 : 2010-01-31
Date1 is before Date2

3. Calender.before(), Calender.after() and Calender.equals()

Example to compare two java.util.Calendar

TestDate3.java

package com.mkyong.date;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class TestDate3 {

    public static void main(String[] args) throws ParseException {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date date1 = sdf.parse("2009-12-31");
        Date date2 = sdf.parse("2010-01-31");

        System.out.println("date1 : " + sdf.format(date1));
        System.out.println("date2 : " + sdf.format(date2));

        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        cal1.setTime(date1);
        cal2.setTime(date2);

        if (cal1.after(cal2)) {
            System.out.println("Date1 is after Date2");
        }

        if (cal1.before(cal2)) {
            System.out.println("Date1 is before Date2");
        }

        if (cal1.equals(cal2)) {
            System.out.println("Date1 is equal Date2");
        }
    }

}

Output

date1 : 2009-12-31
date2 : 2010-01-31
Date1 is before Date2

4. Java 8

In Java 8, you can use the new isBefore(), isAfter(), isEqual() and compareTo() to compare LocalDate, LocalTime and LocalDateTime.

Review the following example to compare two java.time.LocalDate

TestDate4.java

package com.mkyong.date;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

public class TestDate4 {

    public static void main(String[] args) {

        DateTimeFormatter sdf = DateTimeFormatter.ofPattern("yyyy-MM-dd");
        LocalDate date1 = LocalDate.of(2009, 12, 31);
        LocalDate date2 = LocalDate.of(2010, 01, 31);

        System.out.println("date1 : " + sdf.format(date1));
        System.out.println("date2 : " + sdf.format(date2));

        System.out.println("Is...");
        if (date1.isAfter(date2)) {
            System.out.println("Date1 is after Date2");
        }

        if (date1.isBefore(date2)) {
            System.out.println("Date1 is before Date2");
        }

        if (date1.isEqual(date2)) {
            System.out.println("Date1 is equal Date2");
        }

        System.out.println("CompareTo...");
        if (date1.compareTo(date2) > 0) {

            System.out.println("Date1 is after Date2");

        } else if (date1.compareTo(date2) < 0) {

            System.out.println("Date1 is before Date2");

        } else if (date1.compareTo(date2) == 0) {

            System.out.println("Date1 is equal to Date2");

        } else {

            System.out.println("How to get here?");

        }
    }

}

Output

date1 : 2009-12-31
date2 : 2010-01-31
Is...
Date1 is before Date2
CompareTo...
Date1 is before Date2

References

  1. Date CompareTo JavaDoc
  2. Calendar before after JavaDoc
  3. LocalDate JavaDoc
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