Group by field name in Java

Question

I\'m trying to group Java objects by their field, i.e Person.java

public class Person {
    String name;
    String surname;
    ....
}

Answer 1

You can use Multimap and groupBy() from Eclipse Collections

MutableList allPeople = Lists.mutable.empty();
MutableListMultimap multimapByName = allPeople.groupBy(Person::getName);

If you can't change the type of allPeople from List

List allPeople = new ArrayList<>();
MutableListMultimap multimapByName = 
     ListAdapter.adapt(allPeople).groupBy(Person::getName);

Note: I am a contributor to Eclipse Collections.