JPA/hibernate sorted collection @OrderBy vs @Sort

Question

I would like to have a collection of child objects (here cat-kitten example) that are ordered. And keep their order on adding of new elements.

@Entity 
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Answer 1

The latest version of Hibernate uses new annotations to accomplish this:

@SortNatural
@OrderBy("name ASC")
private SortedSet kittens = new TreeSet<>();

There are two parts to this:

1. The @OrderBy annotation specifies that an order by clause should be added to the database query when fetching the related records.
2. The @SortNatural annotation assumes that Kitten implements the Comparable interface and uses that information when constructing the TreeSet instance. Note that you can replace this with the @SortComparator annotation, which allows you to specify a Comparator class that will be passed to the TreeSet constructor.

See documentation: https://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html#collections-sorted-set