I would like to the list to be sorted on the basis of the employeeID of Employee class. How can I do it?

Question

If an Employee class is present and its objects are added in an arrayList.

Comments

please avoid your homework question

Answer 1

1.Implement Comparable interface for the Employee class and override the compareTo(Object obj) method in which compare the employeeID of person
2.Then call Collections.sort() method and pass that list as an argument.

Now consider that Employee class is a jar file.
1.Since Comparable interface cannot be implemented, create Comparator and override the compare(Object obj, Object obj1) method .
2.Call Collections.sort() on the list and pass comparator as an argument

Answer 2

Treeset will be a better DS to use for this usecase.