how to calculate age on entry of dob in java
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class AgeCalculator
{
private static Age calculateAge(Date birthDate)
{
int years = 0;
int months = 0;
int days = 0;
//create calendar object for birth day
Calendar birthDay = Calendar.getInstance();
birthDay.setTimeInMillis(birthDate.getTime());
//create calendar object for current day
long currentTime = System.currentTimeMillis();
Calendar now = Calendar.getInstance();
now.setTimeInMillis(currentTime);
//Get difference between years
years = now.get(Calendar.YEAR) - birthDay.get(Calendar.YEAR);
int currMonth = now.get(Calendar.MONTH) + 1;
int birthMonth = birthDay.get(Calendar.MONTH) + 1;
//Get difference between months
months = currMonth - birthMonth;
//if month difference is in negative then reduce years by one
//and calculate the number of months.
if (months < 0)
{
years--;
months = 12 - birthMonth + currMonth;
if (now.get(Calendar.DATE) < birthDay.get(Calendar.DATE))
months--;
} else if (months == 0 && now.get(Calendar.DATE) < birthDay.get(Calendar.DATE))
{
years--;
months = 11;
}
//Calculate the days
if (now.get(Calendar.DATE) > birthDay.get(Calendar.DATE))
days = now.get(Calendar.DATE) - birthDay.get(Calendar.DATE);
else if (now.get(Calendar.DATE) < birthDay.get(Calendar.DATE))
{
int today = now.get(Calendar.DAY_OF_MONTH);
now.add(Calendar.MONTH, -1);
days = now.getActualMaximum(Calendar.DAY_OF_MONTH) - birthDay.get(Calendar.DAY_OF_MONTH) + today;
}
else
{
days = 0;
if (months == 12)
{
years++;
months = 0;
}
}
//Create new Age object
return new Age(days, months, years);
}
public static void main(String[] args) throws ParseException
{
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
Date birthDate = sdf.parse("29/11/1981");
Age age = calculateAge(birthDate);
System.out.println(age);
}
}