How to parse yyyymm data format to Month, YYYY format in Java?

Question

I have a string value which is equal to "202004". how can I convert it to "April, 2020" in Java?

Answer 1

I would use java.time for a task like this.

You can define two java.time.format.DateTimeFormatter instances (one for parsing the input string to java.time.YearMonth and another for formatting the obtained YearMonth to a string of the desired format).

Define a method like this one:

public static String convert(String monthInSomeYear, Locale locale) {
    // create something that is able to parse such input
    DateTimeFormatter inputParser = DateTimeFormatter.ofPattern("uuuuMM");
    // then use that formatter in order to create an object of year and month
    YearMonth yearMonth = YearMonth.parse(monthInSomeYear, inputParser);
    /*
     * the output format is different, so create another formatter
     * with a different pattern. Please note that you need a Locale
     * in order to define the language used for month names in the output.
     */
    DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern(
                                            "MMMM, uuuu",
                                            Locale.ENGLISH
                                        );
    // then return the desired format
    return yearMonth.format(outputFormatter);
}

then use it, e.g. in a main method:

public static void main(String[] args) {
    // your example input
    String monthInAYear = "202004";
    // use the method
    String sameMonthInAYear = convert(monthInAYear, Locale.ENGLISH);
    // and print the result
    System.out.println(sameMonthInAYear);
}

The output will be this:

April, 2020