Convert Month String to Integer in Java

Question

Given a month string such as:

    "Feb"
or
    "February"

Is there any core Java or third party library functionality that would allow you to convert this string to the corresponding month number in a locale agnostic way?

Solution 1

An alternative to SimpleDateFormat using Joda time:

    import org.joda.time.DateTime;
    import org.joda.time.format.DateTimeFormat;
    import org.joda.time.format.DateTimeFormatter;
    ...

    // if default locale is ok simply omit '.withLocale(...)'
    DateTimeFormatter format = DateTimeFormat.forPattern("MMM");
    DateTime instance        = format.withLocale(Locale.FRENCH).parseDateTime("août");  

    int month_number         = instance.getMonthOfYear();
    String month_text        = instance.monthOfYear().getAsText(Locale.ENGLISH);

    System.out.println( "Month Number: " + month_number );
    System.out.println( "Month Text:   " + month_text   );

    OUTPUT:
        Month Number: 8
        Month Text:   August

Solution 2

You could parse the month using SimpleDateFormat:

    Date date = new SimpleDateFormat("MMM", Locale.ENGLISH).parse("Feb");
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    int month = cal.get(Calendar.MONTH);
    System.out.println(month == Calendar.FEBRUARY);

Be careful comparing int month to an int (it does not equal 2!). Safest is to compare them using Calendar's static fields (like Calendar.FEBRUARY).

Solution 3

Java 8 solution:

DateTimeFormatter parser = DateTimeFormatter.ofPattern("MMM")
                                            .withLocale(Locale.ENGLISH);
TemporalAccessor accessor = parser.parse("Feb");
System.out.println(accessor.get(ChronoField.MONTH_OF_YEAR));  // prints 2

Solution 4

SimpleDateFormat.parse.

Solution 5

you could just set up a switch statment, something like this (below). I'm posting this in case anyone wants a simple, easy to understand solution I know I would have wanted it before I typed this up:

switch(input2) {
            case "january":
            case "jan":
                input2 = "1";
            break;

            case "febuary":
            case "feb":
                input2 = "2";
            break;

            case "march":
            case "mar":
                input2 = "3";
            break;

            case "april":
            case "apr":
                input2 = "4";
            break;

            case "may":
                input2 = "5";
            break;

            case "june":
            case "jun":
                input2 = "6";
            break;

            case "july":
            case "jul":
                input2 = "7";
            break;

            case "august":
            case "aug":
                input2 = "8";
            break;

            case "september":
            case "sep":
            case "sept":
                input2 = "9";
            break;

            case "october":
            case "oct":
                input2 = "10";
            break;

            case "november":
            case "nov":
                input2 = "11";
            break;

            case "december":
            case "dec":
                input2 = "12";
            break;
            }

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