Hello!
Thanks for your help....Dana!
I know the application I want to develop is difficult and there are
many concerns to deal with. For this reason I posted in the forum
to know if someone have already developed an application like this
and so could help me.
So any hint or link about one or more concerns to create a PUSH service
will be welcome! :))
Thanks in advance everybody!
Luca
-----Messaggio originale-----
Da: A mailing list for discussion about Sun Microsystem's Java Servlet
API Technology. [mailto:[EMAIL PROTECTED]]Per conto di dana
Inviato: marted� 20 aprile 2010 9.35
A: [EMAIL PROTECTED]
Oggetto: Re: R: How can I implement a PUSH service in Java?
Hi... I am the newest of newbies however the following comments may be of
help..
> 1) What do you mean with "digest"?
Mailing lists (such as this one) frequently offer an option where
subscribers receive clumps of posts 10 or 20 at a time rather than each one
individually, thereby reducing mail volume
Your other concerns seem to revolve around volume of information, so.. is
this information online and reliably archived? If so surely the url is
sufficient?
hope that helps a little
Dana
>
> 2) Do you think it is a good idea to let the user choose the time period
> after that he wants to rececive the notifications?
>
> 3) How can I detect and dump that information that the users don't want?
> Some new users could arrive and could want the information I dumped!
>
> 4) How would you implement the push-service and activate it? Would you use
> J2EE API
> and build the Java service as a Java program standalone?
>
> Let me know, please.
>
> Thanks a lot in advance!!
>
> Luca
>
>
> -----Messaggio originale-----
> Da: A mailing list for discussion about Sun Microsystem's Java Servlet
> API Technology. [mailto:[EMAIL PROTECTED]]Per conto di Dror
> Matalon
> Inviato: sabato 20 aprile 2002 8.54
> A: [EMAIL PROTECTED]
> Oggetto: Re: How can I implement a PUSH service in Java?
>
>
> It really depends on how many users and how much information you're trying
> to process, but here's some ballpark ideas.
>
> On Sat, Apr 20, 2002 at 08:46:44AM +0200, Luca Ventura wrote:
> > Hello everybody!
> >
> > I would like implement a PUSH service in Java for my Web site. What I
> would
> > like to di is: when a user connects to my web site he can compile a form
> > where he chooses the type of data he wants to receive in his mailbox
(eg.
> > newsletters about sport, culture, and so on) or in his mobile-phone
> (through
> > SMS messages) using Javamail and JMS technologies. As soon as the data
> that
> > he needs is available I can send it to him by e-mail or SMS (as he
> prefers).
> > I have some doubts about the following points:
> >
> > 1)How can I implement (in Java )the PUSH engine that collects the
> > preferences of the users and sends information (by e-mail and sms) to
> them?
> > I mean...must I use a servlet or a Java-program standalone always
running
> > (in this second case I can insert a "while (true) do..." cycle in the
body
> > so that the program never ending...)?
>
> I'd collect the information in a servlet. The push would be done by a
> different
> program.
>
> >
> > 2)How can I store the information about the preferences of the user? I
> think
> > I must use necessarily a dabatase: in fact the Java service (program) or
> the
> > servlet could go down (for some reason) and all the information about
the
> > user would be lost. Am I right?
>
> Yep. Collect the info from the user and store it in the database.
>
> >
> > 3)How can I detect when a new type of data for the user is available and
I
> > must send it to him? Of course I must store the data I can send to the
> user
> > in a database (that is to say the news about sport, culture, etc), but
how
> > can I recognize when a particular type of information for a user is
> > available and it is time to send it to him? I though the following
> solution:
> >
> > a)After a fixed period of time T for every user I can periodically scan
> the
> > database where I stored the information about the news,
> > b) I search the type of the news that the user is looking for and I get
> the
> > up-tp-date news that I haven't sent to him yet.
> > c) I send the news to the user.
> >
> > Anyway in this solution I have the following problems:
> >
> > 1) I can have thousands of users and of news in the database: so I have
to
> > do thousands of searches in the database after a period T (this can take
> > seconds, minute, or hours) even if there is no new information to send
to
> > any user, and this isn't very efficient. Maybe the best solution would
be
> to
> > detect when a new information is inserted in the "database of the news"
> and
> > only in that moment to search for the user that need it, or not?
> >
> > 2) In this second case....how can I listen (detect) when a new
> "information"
> > arrives and is stored in the database?
> >
> > 3) I could search for the users to whom to send new data WHEN I am sure
a
> > new information is arrived AND AT LEAST WHEN a fixed period of time T is
> > passed (I would combine the two techniques): in this way I could reduce
> the
> > overhead fo the searches in the database. What do you think about?
> >
> > 4) How can get from the "database" ONLY that news I haven't already sent
> to
> > the user? I think wouldn't be a good idea to send to the user two times
> the
> > same news!!
>
> You're not saying how the data gets to you, how big it is, how often you
> want to send email to your users. If new info comes in every 5 minutes,
> will your users really want to get the email every 5 minutes or would they
> want it collected and sent as a digest?
>
>
> It's not clear that you even want to store the news in the database. You
> might just want to grab it as it comes in, (how is it coming in, anyway?)
> and send it to the users that want it and dump the rest. That would
> make sense, for instance if you're getting 250Megs of data /hour and
> you're only feeding your users 1 Meg /hour. Why store the other 249 Meg
> that you don't need.
>
> As far as looking up thousands of records in the database, that's not
> really a problem. The database can look up thousands of rows in seconds
> as long as the data is not really big.
>
> >
> >
> > Given that to implement a push engine is very difficult any hint (and
any
> > useful link) on the argument is appreciated.
> >
> > I thank you for the help and the patience in advance.
> >
> > Luca
> >
> >
>
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> >
>
> --
>
> Dror Matalon
> Zapatec Inc
> 1700 MLK Way
> Berkeley, CA 94709
>
>
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