Data Access Object

[bhumireddy reddy]

Hi to all,

Can any one help me by giving the DAO example code. and let me know the process of dao.

[Jeanne Boyarsky]

Bhumireddy,
Welcome to JavaRanch!

Have you seen Sun's DAO description page yet? It has a good description and example.

[ravi bhosale]

Hi following code shows abstraction between business layer and data access layer. data access can be any like using JDBC or Hibernate.


The DAO Factory
public abstract class DAOFactory
{
public static final DAOFactory HIBERNATE =
new com.vmware.vcp.dao.hibernate.HibernateDAOFactory();

public static final DAOFactory JDBC =
new com.vmware.vcp.dao.jdbc.JDBCDAOFactory();


public static final DAOFactory DEFAULT = HIBERNATE;
public static final DAOFactory getDAOFactory()
{
return DEFAULT;
}

public abstract CustomerDAO getCustomerDAO();
}

The Hibernate DAO Factory
public class HibernateDAOFactory extends DAOFactory
{
public CustomerDAO getCustomerDAO()
{
return new CustomerDAOHibernate(getCurrentSession(Constants.Hibernate.MASTER_SESSION_FACTORY_NAME));
}
}


The Customer DAO interface
public interface CustomerDAO {
public Customer findCustomerForUserId(String id, boolean lock);
}

The concrete impl of customer dao
public class CustomerDAOHibernate implements CustomerDAO
{
public Customer findCustomerForUserId(String id, boolean lock)
{
// Database access code
}
}

Business layer code

DAOFactory df = DAOFactory.getDAOFactory();
CustomerDAO custDao = df.getCustomerDAO();
custDao.findCustomerForUserId(UserId, true);