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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