How to use hibernate criteria to return only one element of an object instead the entire object?

Question

I\'m trying to get only the list of id of object bob for example instead of the list of bob. It\'s ok with a HQL request, but I would know if it\'s possible using criteria ?

Answer 1

SessionFactory sessionFactory;    
Criteria crit=sessionFactory.getCurrentSession().createCriteria(Model.class);
crit.setProjection(Projections.property("id"));
List result = crit.list();

This code code will give you list of ids in the model class like [1,2,3]. if you wants to get the array list like [{"id":1},{"id":2}] then use the following code

SessionFactory sessionFactory;    
Criteria crit=sessionFactory.getCurrentSession().createCriteria(Model.class); 
crit.setProjection(Projections.property("id").as("id")); 
List result = crit.setResultTransformer(Criteria.ALIAS_TO_ENTITY_MAP).list();