Java Utililty Methods Month Day

Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
String temp = sdf.format(date);
String firstDayInMoth = "";
firstDayInMoth = temp + "-01";
return firstDayInMoth;

Calendar calendar = Calendar.getInstance();
return calendar.get(Calendar.DAY_OF_MONTH) == 1;

try {
    Date today = new Date();
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(today);
    calendar.add(Calendar.MONTH, 1);
    calendar.set(Calendar.DAY_OF_MONTH, 1);
    calendar.add(Calendar.DATE, -1);
    Date lastDayOfMonth = calendar.getTime();
...

int m1 = cal.get(Calendar.MONTH);
cal.add(Calendar.DAY_OF_MONTH, 1);
int m2 = cal.get(Calendar.MONTH);
cal.add(Calendar.DAY_OF_MONTH, -1);
return m1 != m2;

Calendar cal = Calendar.getInstance();
cal.set(Calendar.DATE, 1);
cal.add(Calendar.DATE, -1);
return String.valueOf(dfDdMMMYYYY.format(cal.getTime()));

Calendar calendar = Calendar.getInstance();
Calendar cpcalendar = (Calendar) calendar.clone();
cpcalendar.set(Calendar.DAY_OF_MONTH, 1);
cpcalendar.add(Calendar.MONTH, 1);
cpcalendar.add(Calendar.DATE, -1);
String date = yyyyMMdd.format(new Date(cpcalendar.getTimeInMillis()));
return date;

Calendar cal = Calendar.getInstance();
Date date = null;
try {
    date = new SimpleDateFormat("yyyyMMdd").parse(batdate);
} catch (ParseException e) {
    e.printStackTrace();
cal.setTime(date);
...

return lastDayOfMonth(src, "yyyyMMdd");

SimpleDateFormat sdf = new SimpleDateFormat(DATE_PATTERN);
Date curDate = new Date(System.currentTimeMillis());
Calendar calendar = Calendar.getInstance();
calendar.setTime(curDate);
calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) - 1);
calendar.set(Calendar.DAY_OF_MONTH, 1);
return sdf.format(calendar.getTime());