How do I calculate someone's age in Java?

Question

I want to return an age in years as an int in a Java method. What I have now is the following where getBirthDate() returns a Date object (with the birth date ;-)):

Answer 1

With the date4j library :

int age = today.getYear() - birthdate.getYear();
if(today.getDayOfYear() < birthdate.getDayOfYear()){
  age = age - 1; 
}