Trying to understand factory pattern - having some problems

Question

hi,
I am tryin to learn the implementation of Factory design pattern and I came across this link after searching this forums:
http://java.sun.com/blueprints/corej2eepatterns/Patterns/DataAccessObject.html
My question is:
In the example they have different DAOFactories that have the database specific details like:
// Cloudscape concrete DAO Factory implementation
import java.sql.*;
public class CloudscapeDAOFactory extends DAOFactory {
  public static final String DRIVER=
    "COM.cloudscape.core.RmiJdbcDriver";
  public static final String DBURL=
    "jdbc:cloudscape:rmi://localhost:1099/CoreJ2EEDB";
  // method to create Cloudscape connections
  public static Connection createConnection() {
    // Use DRIVER and DBURL to create a connection
    // Recommend connection pool implementation/usage
  public CustomerDAO getCustomerDAO() {
    // CloudscapeCustomerDAO implements CustomerDAO
    return new CloudscapeCustomerDAO();
  public AccountDAO getAccountDAO() {
    // CloudscapeAccountDAO implements AccountDAO
    return new CloudscapeAccountDAO();
  public OrderDAO getOrderDAO() {
    // CloudscapeOrderDAO implements OrderDAO
    return new CloudscapeOrderDAO();
}But in my application I have stored all the database specific information in the server.xml of my tomcat server.So,how can I read different database configuration information for different databases like Oracle,Cloudbase,MySQL etc ????
Please help.

Answer 1

Thanks duffmo,
But atleast provide some link then that shows wats inHere's two:
http://www.springframework.org
http://www-128.ibm.com/developerworks/java/library/j-dao/
Personally, I don't worry about DAO factory classes.
If I have a class Foo that I want to persist I'll have a companion DAO interface that will look like this:
public interface FooDao
    public Foo find(long id);
    public List<Foo> findAll();
    public void saveOrUpdate(Foo foo);
    public void delete(Foo foo);
}There are more finders if I have other candidate keys.
I want to have all the datasource information out of
my code in server.xml,context .xml or some other xml
file from which my java code should read the
information,so which is the ideal way to do if you
want to make your application generic in the sense it
can be used with any database.Yes, I agree. Your database stuff will be in the Spring context and your app server's JNDI data source.
%