Comparing ENUMs in Java 6 - enums

Question

I am trying to find best way to compare Enums in Java 6.
Say, I have an ENUM of Ticket Types which can be associated with a Traveler. If there is a list of travelers, I would like to know the traveler with the highest class of travel.
I can iterate thru the list of travelers, create a Set of unique TicketTypes, Convert to List, Sort them, Return the last element as the highest. I would like to know if there is a better way to do this?
public enum TicketType {
ECONOMY_NON_REF(1,"Economy Class, Non-Refundable"),
ECONOMY_REF(2,"Economy Full Fare Refundable"),
BUSINESS(3,"Business Class"),
FIRST_CLASS(4,"First Class, Top of the world");
private String code;
private String description;
}
public class Traveler {
private TicketType ticketType;
public Traveler(TicketType ticketType) {
this.ticketType = ticketType;
}
}
#Test
public testCompareEnums{
List<Traveler> travelersGroup1 = new ArrayList<Travelers>();
travelersGroup1.add(new Traveler(TicketType.ECONOMY_REF));
travelersGroup1.add(new Traveler(TicketType.BUSINESS));
travelersGroup1.add(new Traveler(TicketType.ECONOMY_REF));
travelersGroup1.add(new Traveler(TicketType.ECONOMY_NON_REF));
//What is the best way to find the highest class passenger in travelersGroup1.
assertEquals(TicketType.BUSINESS, getHighestClassTravler(travelersGroup1));
List<Traveler> travelersGroup2 = new ArrayList<Travelers>();
travelersGroup2.add(new Traveler(TicketType.ECONOMY_REF));
travelersGroup2.add(new Traveler(TicketType.ECONOMY_NON_REF));
travelersGroup2.add(new Traveler(TicketType.ECONOMY_REF));
travelersGroup2.add(new Traveler(TicketType.ECONOMY_NON_REF));
assertEquals(TicketType.ECONOMY_REF, getHighestClassTravler(travelersGroup2));
}
private CredentialType getHighestClassTraveler(List travelers){
Set uniqueTicketTypeSet = new HashSet();
for (Traveler t: travelers) {
uniqueTicketTypeSet.add(t.getTicketType());
}
List<TicketType> uniqueTicketTypes = new ArrayList<TicketType>(uniqueTicketTypeSet);
Collections.sort(uniqueTicketTypes);
return uniqueTicketTypes.get(uniqueTicketTypes.size()-1);
}

Answer 1

There's a lot of problems with the code that you posted (it won't compile without fixing a lot of errors), but the easiest way is to make Traveler implement the Comparable interface, like so:
public int compareTo(Traveler other) {
return this.getTicketType().compareTo(other.getTicketType());
}
Then to find the the Traveler with the highest TicketType, you can simply do:
Collections.max(travelers);