Person.java, name, title, birth place and date. Contains some default static persons.

Person.java

package history;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * The Person class, containing the important stuff about a person.
 * @author mr.bear
 */
public class Person
{

    public static final long MILLISECONDS_IN_A_YEAR = 365l * 24l * 60l * 60l * 1000l;
    public static final Person gosling = new Person("James", "Gosling", "Father of Java", "1955-05-19", "Calgary");
    public static final Person babbage = new Person("Charles", "Babbage", "Mathematician", "1791-12-26", "London");
    public static final Person turing = new Person("Alan", "Turing", "Mathematician", "1912-06-23", "London");
    public static final Person knuth = new Person("Donald", "Knuth", "Computer scientist", "1938-01-10", "Milwaukee");
    public static final Person dijkstra = new Person("Edsger", "Dijkstra", "Computer scientist", "1930-05-11", "Rotterdam");
    private String firstName;
    private String lastName;
    private String jobTitle;
    private Date birthDate;
    private String cityOfBirth;

    public Person(String firstName, String lastName, String jobTitle, String birthDate, String cityOfBirth)
    {
        this.firstName = firstName;
        this.lastName = lastName;
        this.jobTitle = jobTitle;
        try
        {
            if (birthDate != null)
            {
                this.birthDate = new SimpleDateFormat("yyyy-MM-dd").parse(birthDate);
            }
        } catch (ParseException ex)
        {
            Logger.getLogger(Person.class.getName()).log(Level.SEVERE, null, ex);
        }
        this.cityOfBirth = cityOfBirth;
    }

    public Person()
    {
    }

    public String getFirstName()
    {
        return firstName;
    }

    public void setFirstName(String firstName)
    {
        this.firstName = firstName;
    }

    public String getLastName()
    {
        return lastName;
    }

    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }

    public Date getBirthDate()
    {
        return birthDate;
    }

    public void setBirthDate(Date birthDate)
    {
        this.birthDate = birthDate;
    }

    public String getJobTitle()
    {
        return jobTitle;
    }

    public void setJobTitle(String jobTitle)
    {
        this.jobTitle = jobTitle;
    }

    public String getCityOfBirth()
    {
        return cityOfBirth;
    }

    public void setCityOfBirth(String cityOfBirth)
    {
        this.cityOfBirth = cityOfBirth;
    }

    public Long getAge()
    {
        if (birthDate == null)
        {
            return null;
        }
        Calendar now = Calendar.getInstance();
        Calendar birth = Calendar.getInstance();
        birth.setTime(birthDate);
        return ((now.getTimeInMillis() - birth.getTimeInMillis()) / (MILLISECONDS_IN_A_YEAR));
    }
}