Hibernate @OneToMany remove child from list when updating parent

Instead of replacing the collection (team.setUserTeamRoles(new HashSet<UserTeamRole>());) you have to clear() the existing one. This happens because if Hibernate loads the entity (and its collections) from DB, it “manages” them, ie. tracks their changes. Generally when using Hibernate it’s better not to create any setters for collections (lists, sets). Create only the getter, and clear the collection returned by it, ie:

team.getUserTeamRoles().clear();

Another thing is that you miss orphan deletion (ie. delete child object when it’s removed from collection in the parent). To enable it, you need to add @OneToMany(orphanRemoval=true) in owning entity.