Building a Simple Application - Beginning Hibernate: From Novice to Professional - page 56

import sample.AdException;
import sample.entity.Advert;
import sample.entity.User;
public class AdvertDAO extends DAO {
public Advert create(String title, String message, User user)
throws AdException {
try {
begin();
Advert advert = new Advert(title, message, user);
getSession().save(advert);
commit();
return advert;
} catch (HibernateException e) {
rollback();
throw new AdException("Could not create advert", e);
}
}
public void delete(Advert advert)
throws AdException
{
try {
begin();
getSession().delete(advert);
commit();
} catch (HibernateException e) {
rollback();
throw new AdException("Could not delete advert", e);
}
}
}
If you compare the amount of code required to create our DAO classes here with the
amount of code that would be required to implement them using the usual JDBC approach,
you will see that Hibernate's logic is admirably compact.
The Example Client
Listing 3-23 shows the example code tying this together. Of course, this isn't a full application,
but you now have all the DAOs necessary to manage the advertisement database. This exam-
ple gives a flavor of how they can be used.
The code should be run with the tasks in the Ant script delivered in Listing 3-1. After run-
ning the exportDDL task to create the empty database, you should run the createUsers and
createCategories tasks to provide initial users and categories, and then the postAdverts task to
place advertisements in the database. Finally, run the listAdverts task to display the saved data.
The code invoking the DAOs to perform the tasks in question is shown in Listing 3-23.