DAO testing

[techyworld]

Hi i need some help, how to unit test a DAO?
here my code:

@Transactional
public class ProjectDaoImpl extends HibernateDaoSupport implements ProjectDao {

    Log logger = LogFactory.getLog(this.getClass());
    private String message;

    /**
     * {@inheritDoc}
     */
    public List<User> retrieveAll() {
        return this.getHibernateTemplate().loadAll(User.class);
    }

    /**
     * {@inheritDoc}
     */
    public boolean saveOrUpdateUser(User user) {
        boolean res = false;
        try {
            this.getHibernateTemplate().saveOrUpdate(user);
            res = true;
        } catch (DataAccessException e) {
            res = false;
            this.logger.error("DataAccessException", e);
        }
        return res;
    }

    /**
     * {@inheritDoc}
     */

    @SuppressWarnings("unchecked")
    public User retrieveUserById(Long id) {
        User user = null;
        DetachedCriteria criteria = DetachedCriteria.forClass(User.class);
        Criterion criterion = Restrictions.eq("user_id", id);
        criteria.add(criterion);
        try {
            List<User> users = this.getHibernateTemplate().findByCriteria(criteria);
            if (users != null && users.size() > 0)              user = users.get(0);
        } catch (DataAccessException e) {
            this.logger.error("DataAccessException", e);
        }

        return user;
    } 



/**
 * {@inheritDoc}
 */
@SuppressWarnings("unchecked")
public List<User> retrieveUserByCriteria(DetachedCriteria criteria) {
    List<User> users = null;
    try {
        users = this.getHibernateTemplate().findByCriteria(criteria);
    } catch (DataAccessException e) {
        this.logger.error("DataAccessException", e);
    }
    return users;
}

/**
 * {@inheritDoc}
 */
public boolean deleteUser(User user) {
    boolean res = false;
    try {
        this.getHibernateTemplate().delete(user);
        res = true;
    } catch (DataAccessException e) {
        this.logger.error("DataAccessException", e);
    }
    return res;
}

}

[stultuske]

... write unit tests for them and run them.
since I don't know what your expected outcome should be, can't really help you much.

but, for adding:

1. test if the nr of elements is increased by one
2. verify your new element is in your list

for deleting:

1. verify the element is in the list
2. verify that after the delete there is one element less
3. verify that your object is no longer in the list

...

[techyworld]

Actually I have an interface UserDao, then UserDaoImpl which implement the interface. and now i need to do unit testing on UserDaoImpl. These methods are communicating directly to the database. will it be the same? I can't even create an instance of the class UserDaoImpl. Why this issue?