Use following code to calculate the age in java. Input parameter is calendar which contains b'day year, month, day.
public int calculateAge(Calendar bcalendar) {
Calendar today = Calendar.getInstance();
int age = today.get(Calendar.YEAR) - bcalendar.get(Calendar.YEAR);
if (today.get(Calendar.DAY_OF_YEAR) < bcalendar.get(Calendar.DAY_OF_YEAR)) {
age--;
}
return age;
}