can you send the url for the article?
-sourabh
----- Original Message -----
From: ShriKant Vashishtha <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, February 01, 2002 9:50 AM
Subject: Re: Connection in JSPs?
> Hi All,
>
> I have found a very good article which does solve most of the problems
> using design patterns.
> The article "Applying Patterns to JDBC: Buiding a lightweight
> Object-Relational Mapping
> Framework" by Frank Sauer appeared in JavaReport magazine in May, 2001.
>
> Thanks all,
> -ShriKant
>
> "A mailing list for discussion about Sun Microsystem's Java Servlet API
> Technology." wrote:
>
> > Does somebody has some more clue about this issue.......................
> > Please enlighten.
> >
> > -ShriKant
> >
> > "A mailing list for discussion about Sun Microsystem's Java Servlet API
> > Technology." wrote:
> >
> > > First of all I want to clarify that I am not using entity beans to
> access
> > > database. I
> > > appreciate your understanding about the usage of J2EE pattern. This
> > pattern
> > > is all about
> > > resource independency, that means, after using that pattern, I need
not
> > > worry whether my
> > > query is being processed by Oracle, Sybase, XML datastore etc. But I
> > think
> > > that is a separate
> > > issue (resource independency).
> > >
> > > Here what I am worried of is, it may mean as many classes (read
> > > implementation classes) as
> > > there are tables and queries. It may become difficult to manage when
we
> > > have a large database
> > > and schema. May be I am going to same line where you are. I want to
put
> > > that kind of
> > > implementation in native SQL instead of Java classes. That means,
there
> > > should be some kind
> > > of common interface which could interact with the query parameter,
> query
> > > identifier; and just
> > > pass them to corresponding implemention of SQL. The interface should
be
> > > single controller to
> > > manage it. I don't know how far is it possible. Any takers............
> > >
> > > -ShriKant
> > >
> > > "A mailing list for discussion about Sun Microsystem's Java Servlet
API
> > > Technology." wrote:
> > >
> > > > Well. It all depends on how you access the DB whether thru Entity
> > beans,
> > > > direct Sql drivers etc., As you might know there is a j2ee pattern
> > called
> > > > "Data Access Objects(DAOs)" using which you can do these. It's
> nothing
> > > but
> > > > kind of using the power of interfaces in Java. For example, you can
> > > declare
> > > > an interface with business methods. Let's say you need to access a
> user
> > > > table. Then you may have,
> > > >
> > > > public interface DBAccess{
> > > > public void addUser(UserInfo ui) throws SQLException;
> > > > public void deleteUser(String userId)throws SQLException;
> > > > public void modifyUser(UserInfo modifiedUser)throws SQLException;
> > > > public UserInfo getUser(String userId) throws SQLException;
> > > > public void getUsers()throws SQLException;
> > > > }
> > > >
> > > > You can write implementaion classes for this interface depends on
the
> > > > Database you use. The code to add/modify/delete data into/from a
> > database
> > > > will reside in a single place(implementation classes) which will
lead
> > you
> > > > to a better maintainalbe code.
> > > >
> > > > For example, you may use a RDBMS, ordinary DBMS even flat files. As
> > long
> > > as
> > > > your code talks to an interface, you can plug in the
implementations.
> > > >
> > > > For example you use two kinds of DBs in your code. Then,
> > > > DBAccess db = DBAccessFactory.getInstance("Oracle");
> > > > UserInfo ui = db.getUser("shri");
> > > > db.deleteUser("shri");
> > > > db = DBAccessFactory.getInstance("SQLServer");
> > > > db.addUser(ui);
> > > >
> > > > So even if you change the implementation classes, your code still
> > works.
> > > > I don't prefer going for stored procedures and writing methods which
> > > takes
> > > > a Query as an argument. If you want this only, then that is what
your
> > > > statement/prepared statements do.
> > > >
> > > > -----Original Message-----
> > > > From: ShriKant Vashishtha [mailto:[EMAIL PROTECTED]]
> > > > Sent: Monday, January 28, 2002 5:37 PM
> > > > To: [EMAIL PROTECTED]
> > > > Subject: Re: Connection in JSPs?
> > > >
> > > > Is there a generic approach/pattern/framework by which we just need
> to
> > > > specify the query
> > > > parameter and that will give us the respective response. I want to
> use
> > a
> > > > common interface
> > > > (and put it into a Class) for all the sql ueries for all the JSP
> which
> > > > should not be
> > > > dependent upon the query parameter and type of query. One possible
> > > solution
> > > > I can think of to
> > > > use the stored procedure for all JDBC related work and pass them the
> > > > necessary parameters
> > > > required and get the response in return. But at present I am not
very
> > > sure
> > > > of the pros and
> > > > cons of this strategy. Is there any other possible solution. Please
> > > > enlighten...........
> > > >
> > > > -ShriKant
> > > >
> > > > "A mailing list for discussion about Sun Microsystem's Java Servlet
> API
> > > > Technology." wrote:
> > > >
> > > > > You can write an utility class kind of thing like
> ConnectionPool.java
> > > > which
> > > > > has methods like public Connection getFreeConnection() and public
> > void
> > > > > returnConnection(Connection c).
> > > > > Make sure that you don't close the connections in your JSPs after
> > use.
> > > > Let
> > > > > the same utility class close the connections when it decides they
> are
> > > not
> > > > > necessary.
> > > > > So that you can have the code two aquire a DB connection in one
> > place
> > > > > which will be easier when you might change the server/driver etc
in
> > > > future.
> > > > > -----Original Message-----
> > > > > From: Sumit Mishra [mailto:[EMAIL PROTECTED]]
> > > > > Sent: Monday, January 28, 2002 10:31 AM
> > > > > To: [EMAIL PROTECTED]
> > > > > Subject: Connection in JSPs?
> > > > >
> > > > > Hi,
> > > > >
> > > > > What can be the best way of taking connection in a JSP when u have
> to
> > > > fire
> > > > > a query in almost every JSP? Is the useBean approach ok??
> > > > >
> > > > > Regards,
> > > > > Sumit
> > > >
> > > >
> > >
> >
>
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