java获取给定月份和给定年份的第一个日期和最后一个日期

我试图获取给定月份和年份的第一个日期和最后一个日期。我使用以下代码获取格式为yyyyMMdd的最后一个日期。但不能得到这种格式。此外，我想开始日期以相同的格式。我还在做这个。任何人都可以帮助我修复下面的代码。

I am trying to get the first date and the last date of the given month and year. I used the following code to get the last date in the format yyyyMMdd. But couldnot get this format. Also then I want the start date in the same format. I am still working on this. Can anyone help me in fixing the below code.

public static java.util.Date calculateMonthEndDate(int month, int year) {
    int[] daysInAMonth = { 29, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    int day = daysInAMonth[month];
    boolean isLeapYear = new GregorianCalendar().isLeapYear(year);

    if (isLeapYear && month == 2) {
        day++;
    }
    GregorianCalendar gc = new GregorianCalendar(year, month - 1, day);
    java.util.Date monthEndDate = new java.util.Date(gc.getTime().getTime());
    return monthEndDate;
}

public static void main(String[] args) {
    int month = 3;
    int year = 2076;
    final java.util.Date calculatedDate = calculateMonthEndDate(month, year);
    SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");
    format.format(calculatedDate);
    System.out.println("Calculated month end date : " + calculatedDate);
}