@RequiresSession
  public List<ResourceTypeEntity> findAll() {
    TypedQuery<ResourceTypeEntity> query = entityManagerProvider.get().createQuery("SELECT resourceType FROM ResourceTypeEntity resourceType", ResourceTypeEntity.class);
    return daoUtils.selectList(query);
  }
Find all resource types.

@return all resource types or an empty List
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/ResourceTypeDAO.java