How to fetch liferay entity through custom-finder in custom plugin portlet?

Question

How can we fetch liferay entities through custom-finder using custom SQL?

1. Following is my sql query written in default.xml (_{I have trimmed down the query to the bare minimum so that the logic remains simple. Since it included a few functions and joins we couldn't use DynamicQuery API} ):

   SELECT
       grp.*
   FROM
       Group_
   WHERE
       site = 1
       AND active_ = 1
       AND type_ <> 3
   

2. Relevant code in MyCustomGroupFinderImpl.java:

   Session session = null;
   
   try {
       session = openSession();
   
       // fetches the query string from the default.xml
       String sql = CustomSQLUtil.get(FIND_ONLY_ACTIVE_SITES);
   
       SQLQuery sqlQuery = session.createSQLQuery(sql);
   
       sqlQuery.addEntity("Group_", GroupImpl.class);
       // sqlQuery.addEntity("Group_", PortalClassLoaderUtil.getClassLoader().loadClass("com.liferay.portal.model.impl.GroupImpl"));
   
       return (List<Group>) QueryUtil.list(sqlQuery, getDialect(), 0, QueryUtil.ALL_POS);
   }
   catch (Exception e) {
       throw new SystemException(e);
   }
   finally {
       closeSession(session);
   }
   

This above code won't work as the GroupImpl class is present in portal-impl.jar and this jar cannot be used in custom portlet.

I also tried using sqlQuery.addEntity("Group_", PortalClassLoaderUtil.getClassLoader().loadClass("com.liferay.portal.model.impl.GroupImpl"))
But this above code throws exception:

com.liferay.portal.kernel.exception.SystemException:
    com.liferay.portal.kernel.dao.orm.ORMException:
        org.hibernate.MappingException:
            Unknown entity: com.liferay.portal.model.impl.GroupImpl

But the same code works for our custom-entity, if we write sqlQuery.addEntity("MyCustomGroup", MyCustomGroupImpl.class);.

Thanks

Answer 1

I found out from the liferay forum thread that instead of session = openSession(); we would need to fetch the session from liferaySessionFactory as follows to make it work:

// fetch liferay's session factory
SessionFactory sessionFactory = (SessionFactory) PortalBeanLocatorUtil.locate("liferaySessionFactory");

Session session = null;

try {
    // open session using liferay's session factory
    session = sessionFactory.openSession();

    // fetches the query string from the default.xml
    String sql = CustomSQLUtil.get(FIND_ONLY_ACTIVE_SITES);

    SQLQuery sqlQuery = session.createSQLQuery(sql);

    // use portal class loader, since this is portal entity
    sqlQuery.addEntity("Group_", PortalClassLoaderUtil.getClassLoader().loadClass("com.liferay.portal.model.impl.GroupImpl"));

    return (List<Group>) QueryUtil.list(sqlQuery, getDialect(), 0, QueryUtil.ALL_POS);
}
catch (Exception e) {
    throw new SystemException(e);
}
finally {
    sessionFactory.closeSession(session); // edited as per the comment on this answer
    // closeSession(session);
}

Hope this helps somebody on stackoverflow, also I found a nice tutorial regarding custom-sql which also uses the same approach.