In Java, How do you quicksort an ArrayList of objects in which the sorting field is multiple layers deep?

Question

Basically, I have a Container class called \"Employees\" which has in it an ArrayList. This ArrayList contains \"Employee\" objects, which in turn contain \"EmployeeData\" objec

Answer 1

You can make a comparator, something like:

public class MyComparator implements Comparator
{
  public int compare(Employee e1, Employee e2)
  {
    return e1.getData().getLast().compareTo(e2.getData().getLast());
  }
}

Then use it to sort the list.

Collections.sort(myList, new MyComparator());

Alternatively, you can use a TreeSet to sort on insertion using this comparator or make the Employee a comparable object to sort using Collections or a SortedSet.

public class Employee implements Comperable
{
  ...
  public int compareTo(Employee e)
  {
    return this.getData().getLast().compareTo(e.getData().getLast());
  }
  ...
}