To obtain a connection from a data source, do the following:
Obtain the initial JNDI context.
To guarantee portability between different environments, the code used to retrieve an InitialContext object (in a servlet, in a JSP page, or an EJB) is as follows:
InitialContext ctx = new InitialContext();
Use a JNDI lookup to obtain a data source reference.
To obtain a reference to a data source bound to the JNDI context, look up the data source’s JNDI name from the initial context object. The object retrieved in this way is cast as a DataSource type object:
ds = (DataSource)ctx.lookup(JndiDataSourceName);
Use the data source reference to obtain the connection.
This operation requires the following line of code:
conn = ds.getConnection();
Application Server 6.x and Application Server both follow these technique to obtain a connection from the data source.