Re: Newbie - a question about import and .jar statement
"Mark Space" wrote:
Use "Class.forName()" and supply the driver name as a
parameter to the script or application.
<http://java.sun.com/docs/books/tutorial/jdbc/basics/connecting.html>
Arved Sandstrom wrote:
Other useful references are:
1)
http://java.sun.com/j2se/1.5.0/docs/guide/jdbc/getstart/drivermanager.html
2) http://java.sun.com/j2se/1.5.0/docs/guide/jdbc/getstart/datasource.html
Note that DataSource is preferred if you can use it. As the docs point out,
the advantages of this over using DriverManager are (a) not hardcoding
driver info, and (b) taking advantage of connection pooling and distributed
transactions etc. Of course, as far as (a) is concerned the hardcoding for
DriverManager is strings, not class imports, and these strings can be stored
externally according to best practices. Note that Mark's reference to
Class.forName() is in the context of DriverManager.
>
Using one of these approaches your application code is blissfully unaware of
driver specifics. It only needs to import java.sql.* for the "generic" stuff
like Connection.
Note further that the driver need be loaded but once. It is a common error to
load the driver again and again, often with each connection attempt. You
might think that this only hurts performance a tad, but the real harm is the
mixture of driver-load code into the connection code, breaking encapsulation.
The repeated-load antipattern makes your application unblissfully aware of
driver specifics.
--
Lew