Why should a Comparator implement Serializable?

Question

New to Java. Learning it while working on an Android app. I am implementing a Comparator to sort a list of files and the android docs say that a Comparator should implement Seri

Answer 1

This should help you out : http://docs.oracle.com/javase/7/docs/api/java/util/Comparator.html

Note: It is generally a good idea for comparators to implement java.io.Serializable, as they may be used as ordering methods in serializable data structures (like TreeSet, TreeMap). In order for the data structure to serialize successfully, the comparator (if provided) must implement Serializable.