Question

it is my second time that i play with jpa,

i wrote this pice of code:

   String queryString = "SELECT e.uidprofile, e.profilecode, e.catUso, max(e.zonaClim), e.classePrev, e.beta1, e.beta2, e.beta3, e.beta4"
            + " FROM "
            +  entityClass.getSimpleName()
            + " e "
            + " WHERE e.catUso like :code "
            + " group by e.uidprofile, e.profilecode, e.catUso, e.classePrev, e.beta1, e.beta2, e.beta3, e.beta4"
            + " order by e.uidprofile";

    Query query = entityManager.createQuery(queryString);

    query.setParameter("code", "C" + "%");

    List<SamTbProfileMapping> resultList = query.getResultList();

    ClassLoader c1 = this.getClass().getClassLoader();
    ClassLoader c2 = resultList.getClass().getClassLoader();

    if(resultList.size()>0){
        System.out.println(resultList.get(0).getCatUso());
    }

Debugging it:

• resultList has all the fields of SamTbProfileMapping with the right values
• the count of the objects is right
• after the line List<SamTbProfileMapping> resultList = query.getResultList();
  i get C2 to null and System.out.println(resultList.get(0).getCatUso());
  says that resultList can not be Casted To SamTbProfileMapping

Answer 1

You are retrieving a list of arrays with your query. Not a list of objects.

"Select a, b, c, d, from something" – returns List<Object[]>

Then access separate members in the same order as in query.
For example:

 List<Object[]> myList = query.getResultList();

 MyAClass a1 = (MyAClass) myList.get(0)[0];
 MyBClass b1 = (MyBClass) myList.get(0)[1];

To select an object list you can use:

"select a from MyClass a where ..."

Then

 List<MyClass> myList = query.getResultList();
 MyClass result1 = myList.get(0);