regarding variable passing, craig has done a smash up job of answering
this and other questions in the past. some relevant comments on this
topic can be found in the list archives at:
http://archives.java.sun.com/cgi-bin/wa?S2=servlet-interest&q=setAttribute&s=&f=cmcclanahan%40mytownnet.com&a=&b=
i couldn't find the exact message i was looking for but in the
archives is a message where craig clearly states when one should
consider using Request, Session or ServletContext scoped storage
schemes along with a the relevant 2 to 3 lines of code. the man
should write a book ... anyways ... the basic theme is:
data with which you wish to share across the life of a single
http request and no more should be handled by the
ServletRequest object via the get/set Attribute methods.
data with which you wish to share across multiple requests
for the same user during the lifetime of a single session should
handled by the HttpSession object via the get/set Attribute
methods.
data with which you wish to share across users, sessions and
requests should be handled by the ServletContext object via
the get/set Attribute methods.
note: some of the above is servlet 2.2 specific and may not
directly address servlet 2.1 or lesser implemenations. in
this area the servlet 2.2 spec made the data accessors more
consistent accross the api.
you can store data in other more exotic containers (eg database,
singleton, ejb) but i have a feeling even if you do this some
subset of the associated data will be stored in one or more
of the above mentioned javax.servlet.* constructs.
hope this helps,
- james
Ted Neward wrote:
> I can certainly answer the second one, but I'll defer the first one to
> others more comfortable with the Servlet spec than I.
>
> Using stored procs does for you what using methods to access private data
> does within Java classes: it helps encapsulate the details of the
> underlying database schema. By using stored procs to obtain and/or
> manipulate the entities within the database, your DBAs can shuffle the
> schema around as necessary (to optimize for size, speed, certain queries,
> whatever is necessary) without having to recompile SQL code. (Other
> approaches to achieve this same effect include placing the SQL within text
> files that the application simply reads and executes, but then if the SQL
> changes, all of those "SQL properties" files require updating--not a
> simple chore.)
>
> Since you're using Oracle, you may as well make use of Oracle's rather
> powerful PL/SQL language and syntax. Note that you're still using
> JDBC--you're just using it to make stored proc calls, instead of directly
> executing SQL statements.
>
> Ted Neward
> http://www.javageeks.com/~tneward
>
> On Thu, 11 Nov 1999, Lalith Jayaweera wrote:
>
> > Hi
> > I need Ur help to sort it out following twoe two questions .
> >
> > (1) How can we pass a variable which is used in one servlet to another
> > servlet which will be used later.What am currently doing is creating a
> > session object and putting the value and getting the value back when
> > necessary.Is there any otherway that I can use instead of this one.
> >
> > (2)Rather than using jdbc.. for database access(writing sqlcodes well
> > within the servlet) is there any advantage if I can use stored
> > procedures.(am using
> > oracle as my database server);
> >
> >
> > Thanks in Advance
> > lalith
> >
> > ___________________________________________________________________________
> > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> > of the message "signoff SERVLET-INTEREST".
> >
> > Archives: http://archives.java.sun.com/archives/servlet-interest.html
> > Resources: http://java.sun.com/products/servlet/external-resources.html
> > LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
> >
>
> ___________________________________________________________________________
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> of the message "signoff SERVLET-INTEREST".
>
> Archives: http://archives.java.sun.com/archives/servlet-interest.html
> Resources: http://java.sun.com/products/servlet/external-resources.html
> LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
___________________________________________________________________________
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff SERVLET-INTEREST".
Archives: http://archives.java.sun.com/archives/servlet-interest.html
Resources: http://java.sun.com/products/servlet/external-resources.html
LISTSERV Help: http://www.lsoft.com/manuals/user/user.html
