Is there a Java Obiect that will arrange data in alphabetical order?

Question

Is there a Java Obiect that will arrange data in alphabetical order?
So no matter what order you add or put things into the object it will only return them in alphabetical order.
Edited by: Easter1976 on Nov 5, 2007 9:55 AM

Answer 1

No, you will either have to create a comparator, a sorter, or write the compareTo in such a way that it sorts your data by your wanted fields.
So, given the class Student, you probably want something like this:
public class Student implements Comparable<Student> {
     public int compareTo(Student s) {
          if (getLastName().compareTo(s.getLastName()) != 0)
               return getLastName().compareTo(s.getLastName();
          if (getFirstName().compareTo(s.getFirstName()) != 0)
               return getFirstName().compareTo(s.getFirstName();
          return 0;
}After that, you may sort your list of students with Collections.sort(myListOfStudents);
Alternatively, you may do it like this:
Collections.sort(myListOfTypeSomething, new Comparator<Something>() {
     public int compare(o1, o2) {
          return o1.getAlphaSomething().compareTo(o2.getAlphaSomething());
     });