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

问题

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

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
```

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

回答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.

来源：https://stackoverflow.com/questions/15895484/how-to-fetch-liferay-entity-through-custom-finder-in-custom-plugin-portlet

标签

sql

service

liferay

liferay-6

builder