Java - Sort - Variable comparator

Question

I\'m trying to sort a list of Objects based upon user input. How can I go about having the sort method implement a variant comparator?

Example:

List<         


        

Answer 1

If all "keys" will be linked to getter methods, you can have a static mapping of key/getter that you use in a function:

Note: we'll have to use raw type Comparable as we can't use different Functions> (even if all getters will return Comparable objects, X will vary)

Map> map = new HashMap<>();
map.put("key", s3 -> s3.getKey());
map.put("modified", s3 -> s3.getModified());
// other entries

Then sort using:

objectSummaryList.sort(Comparator.comparing(map.get(compareByKey)));