for a blog post

gistfile1.java

List<PersonEntity> attendees = conference.getAttendees();
Collections.sort(new Comparator<PersonEntity> {
  @Override
  public int sort(PersonEntity person1, PersonEntity person2) {
    final int BOTH_ARE_EQUAL = 0;
    int comparisonByArrivalDateResult = this.compareByArrivalDate(person1, person2);
    if (comparisonByArrivalDateResult == BOTH_ARE_EQUAL) {      
      int comparisonByTicketTierResult = this.compareByTicketTier(person1, person2);
      if (comparisonByTicketTierResult == BOTH_ARE_EQUAL) {
        return this.compareByLastName(person1, person2);
      }
      return comparisonByTicketTierResult
    }
    return comparisonByArrivalDateResult;
  }
  
  private int compareByArrivalDate(person1, person2) {
    ArrivalDate person1ArrivalDate = person1.getArrivalDate(),
                person2ArrivalDate = person2.getArrivalDate();
    if (person1ArrivalDate == null) person1ArrivalDate = DEFAULT_ARRIVAL_DATE;
    if (person2ArrivalDate == null) person2ArrivalDate = DEFAULT_ARRIVAL_DATE;
    return person1ArrivalDate.compareTo(person2ArrivalDate);
  }
  
  private int compareByTicketTier(person1, person2) {
    TicketTier person1TicketTier = person1.getTicketTier(),
               person2TicketTier = person2.getTicketTier();
    if (person1TicketTier == null) person1TicketTier = DEFAULT_TICKET_TIER;
    if (person2TicketTier == null) person2TicketTier = DEFAULT_TICKET_TIER;
    return person1TicketTier.compareTo(person2TicketTier);
  }
  
  private int compareByLastName(person1, person2) {
    String person1LastName = person1.getLastName(),
           person2LastName = person2.getLastName();
    if (person1LastName == null) person1LastName = "";
    if (person2LastName == null) person2LastName = "";
    return person1LastName.compareTo(person2LastName);
  }
});