Issue with DataAccessObject pattern

Question

I am using the patterns described in Core J2EE(TM) Patterns: DataAccessObject pattern
ref : http://java.sun.com/blueprints/corej2eepatterns/Patterns/DataAccessObject.html
Using a DAO and DAO Factory - Client Code
DAOFactory cloudscapeFactory =
DAOFactory.getDAOFactory(DAOFactory.DAOCLOUDSCAPE);
CustomerDAO custDAO =
cloudscapeFactory.getCustomerDAO();
int newCustNo = custDAO.insertCustomer(...);
Customer cust = custDAO.findCustomer(...);
cust.setAddress(...);
cust.setEmail(...);
custDAO.updateCustomer(cust);
custDAO.deleteCustomer(...);
Customer criteria=new Customer();
criteria.setCity("New York");
Collection customersList = custDAO.selectCustomersTO(criteria);
In this client code the corresponding DAO is got and the required methods on that are called, now for each of these method calls a new DB connection is opened and closed.
so if i need to do 10 operations, i need to open 10 connections and close them, is this not a bad approach
is there any way i can manage the whole set of operations by just opening one connection
Any thioughts on this!!!
Thanks
Shivas

Answer 1

Hi Shivas,
In the CloudscapeDAOFactory.createConnection() method, you can do a JNDI lookup to a resource factory which implements a java.sql.DataSource. The resource factory will maintain a pool of connections (a.k.a. connection pooling) for reuse by multiple components.
Example:
Register jdbc/Cloudscape to the resource factory on your J2EE Application Server. Put this code on your DAO:
public static Connection createConnection() {
try {
Context c = new InitialContext();
DataSource ds = (DataSource) c.lookup("java:comp/env/jdbc/Cloudscape");
return ds.getConnection();
} catch (NamingException ne) {
When you close the connection in your methods (ex: findCustomer). The reference is closed and the connection is returned to the pool.
Hope this helps.
- nick