CODEWITHSUNDEEP
java
JDGuide
JDGuide

Reputation: 6525

Find all month names between two given date in java

I need All month/Year names between two given date.I need this out put only on java.

Example :

Input Date:

date 1- 20/12/2011 
date 2- 22/08/2012

Now ,my expected result should be :-

Dec/2011
Jan/2012
Feb/2012
Mar/2012
Apr/2012
May/2012
Jun/2012
Jul/2012
Aug/2012

Could anybody help me. Thanks in Advance.

Upvotes: 10

Views: 15555

Answers (8)

Anonymous
Anonymous

Reputation: 86282

java.time.YearMonth

While the older answers were good answers when written, they are now outdated. Since Java 8 introduced the YearMonth class, this task has been greatly simplified:

    String date1 = "20/12/2011";
    String date2 = "22/08/2012";
    
    DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("dd/MM/uuuu", Locale.ROOT);
    DateTimeFormatter monthFormatter = DateTimeFormatter.ofPattern("MMM/uuuu", Locale.ROOT);
    YearMonth endMonth = YearMonth.parse(date2, dateFormatter);
    for (YearMonth month = YearMonth.parse(date1, dateFormatter);
            ! month.isAfter(endMonth);
            month = month.plusMonths(1)) {
        System.out.println(month.format(monthFormatter));
    }

This prints:

Dec/2011
Jan/2012
Feb/2012
Mar/2012
Apr/2012
May/2012
Jun/2012
Jul/2012
Aug/2012

Please supply an appropriate locale for the second call to DateTimeFormatter.ofPattern() to get the month names in your language. And the first call too to be on the safe side.

See the answer by Arvind Kumar Avinash for a solution that better separates model (YearMonth objects) and user interface (strings to be output) and for a bit more of explanation.

Upvotes: 9

Arvind Kumar Avinash
Arvind Kumar Avinash

Reputation: 79075

java.time

The existing answers are correct. This answer aims to inform about the state of Joda-Time API and solve the question differently.

In March 2014, Java 8 introduced java.time, the modern date-time API. Since then, it's been recommended to switch from the legacy date-time API from the standard library (i.e. java.util date-time API) and the Joda-Time to java.time API. Shown below is a notice on the Joda-Time Home Page:

Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project.

Steps used in this answer:

  1. Parse the given date strings into LocalDate instances by using a DateTimeFormatter with the dd/MM/uuuu pattern.
  2. Obtain YearMonth instances from the above LocalDate instances.
  3. Add all YearMonths to a List<YearMonth> by navigating from the start to end.
  4. In case you need a list of YearMonth in a different string representation: Map each element of the above list into a string using a DateTimeFormatter with the desired format (e.g. MMM/uuuu).

Demo:

public class Main {
    public static void main(String[] args) {
        DateTimeFormatter parser = DateTimeFormatter.ofPattern("dd/MM/uuuu");

        LocalDate date1 = LocalDate.parse("20/12/2011", parser);
        LocalDate date2 = LocalDate.parse("22/08/2012", parser);

        YearMonth start = YearMonth.from(date1);
        YearMonth end = YearMonth.from(date2);

        List<YearMonth> list = new ArrayList<>();

        // Create a list of desired YearMonth
        for (YearMonth ym = start; !ym.isAfter(end); ym = ym.plusMonths(1))
            list.add(YearMonth.from(ym));
        System.out.println(list);

        // In case you need a list of YearMonth in a different string representation
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MMM/uuuu", Locale.ENGLISH);
        // The following line of code will run only from Java 16 onwards:
        // List<String> formattedStrList1 = list.stream()
        //                                      .map(ym -> ym.format(formatter))
        //                                      .toList();
        //
        // In case you are using a version lower than Java 16:
        List<String> formattedStrList2 = list.stream()
                                            .map(ym -> ym.format(formatter))
                                            .collect(Collectors.toList());
        System.out.println(formattedStrList2);
    }
}

Output:

[2011-12, 2012-01, 2012-02, 2012-03, 2012-04, 2012-05, 2012-06, 2012-07, 2012-08]
[Dec/2011, Jan/2012, Feb/2012, Mar/2012, Apr/2012, May/2012, Jun/2012, Jul/2012, Aug/2012]

Online Demo

Learn more about the modern Date-Time API from Trail: Date Time.

Upvotes: 3

Basil Bourque
Basil Bourque

Reputation: 338516

java.time

The modern approach uses the java.time classes. Never use Date/Calendar/SimpleDateFormat and such.

LocalDate

The LocalDate class represents a date-only value, without time-of-day and without time zone. 

LocalDate startLocalDate = LocalDate.of( 2011 , Month.DECEMBER , 20 ) ;  
LocalDate stopLocalDate = LocalDate.of( 2012 , Month.AUGUST , 2 ) ;

YearMonth

When interested only in the year and month, use the class YearMonth.

YearMonth start = YearMonth.from( startLocalDate) ;
YearMonth stop = YearMonth.from( stopLocalDate ) ;

Loop.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "MMM/uuuu" , Locale.US ) ;
int initialCapacity = start.until( stop , ChronoUnit.MONTHS ) ;
List< YearMonth > yearMonths = new ArrayList<>( initialCapacity ) ;
YearMonth ym = start ;
while ( ym.isBefore( stop ) ) {
    System.out.println( ym.format( f ) ) ;  // Output your desired text.
    yearMonths.add( ym ) ;
    ym = ym.plusMonths( 1 ) ;  // Increment to set up next loop.
}

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Upvotes: 0

Kushal Jain
Kushal Jain

Reputation: 3186

So suppose you have these two date. And you can compare it easily by iterating an while loop till fromDate is before toDate.

Date fromDate= new Date("1/4/2016");
Date toDate = new Date("31/12/2016");

int i=0;
while(fromDate.before(toDate)){
    i=i+1;
    fromDate.setMonth(i);
    System.out.println(fromDate);
}

You can add date in list or do whatever do want to do!!!

Upvotes: 0

Eugene
Eugene

Reputation: 120848

Using Joda-Time (since not specified, I assume you could at least have a look at what joda time is):

 LocalDate date1 = new LocalDate("2011-12-12");
 LocalDate date2 = new LocalDate("2012-11-11"); 
 while(date1.isBefore(date2)){
     System.out.println(date1.toString("MMM/yyyy"));
     date1 = date1.plus(Period.months(1));
 }

Upvotes: 12

Uchenna Nwanyanwu
Uchenna Nwanyanwu

Reputation: 3204

Do this

 Calendar cal = Calendar.getInstance();
 cal.setTime(your_date_object);
 cal.add(Calendar.MONTH, 1);

Upvotes: 1

Dan
Dan

Reputation: 1018

Per conversation above. Use Calendar and the add method.

I've not tested this but it's about there:

public static List<Date> datesBetween(Date d1, Date d2) {
    List<Date> ret = new ArrayList<Date>();
    Calendar c = Calendar.getInstance();
    c.setTime(d1);
    while (c.getTimeInMillis()<d2.getTime()) {
        c.add(Calendar.MONTH, 1);
        ret.add(c.getTime());
    }
    return ret;
}

Upvotes: 4

Denys S&#233;guret
Denys S&#233;guret

Reputation: 382130

You can simply use the Calendar class and iterate from one date to the other one by adding a month at each iteration using myCalendar.add(Calendar.MONTH, 1);.

The Calendar class takes care of avoiding overflows and updating the other fields (here the year) for you.

Upvotes: 10

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