I suggest you read the following article:
http://www.javaworld.com/javaworld/jw-12-1999/jw-12-ssj-jspmvc.html
This should help you understand some of the issues you are asking about.
--
Martin Cooper
Tumbleweed Communications
----- Original Message -----
From: "Rakesh Bhat" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, September 10, 2000 10:47 PM
Subject: Re: session
> Hi Laskowski , Brian and Mike,
> Thx a lot for throwing some light on this subject :)
> It is indeed a nice information.
>
> I was under the impression that if you are using jsp for u'r development ,
u need not
> worry much about servlet.
>
> Because,If i remember properly , model 1 is something like JSP receives
the HTTP request
>
> ,JSP passes the information to the bean and get it's things done and build
the response
> object and throw it back.
> (I agree that putting the java code in the jsp file is a bad design.
Infact i too am not
>
> doing that mistake :)
> But what i was wondering was why servlet comes at all when u can pass the
information u
> get from request and session objects of the jsp to a bean and get your
things done!!!!)
>
> Thx a lot again for answering these (trivial?) doubts.
> I am also quite new to this area of jsp and servlets.
> Also , if u could answer me these questions that would be of great help.
>
>
> 1.IS session handling a must process in all web applications ?
> 2.If not ,how does one has to decide whether he/she has to handle session
tracking in
> the application ? or is it a good practice to handle session tracking in
all web
> applications ?
>
>
> Regds
> Rakesh.
>
>
>
>
> Jacek Laskowski wrote:
>
> > Rakesh Bhat wrote:
> > >
> > > Hi Laskowski,
> > >
> > > As I understand , one uses JSP over Servlet because writing a JSP code
is simpler
> > > compared to Servlet.Right ?
> >
> > Yes, but watch out you can fall into a trap and you may mess up your JSP
> > and HTML so nobody will know what is in.
> >
> > > They are 2 different server side technologies.
> > > I agree that JSP finally compiles into a Servlet.But , i don't
understand why one
> > > will use JSP and servlet together ?
> >
> > See below.
> >
> > > When you use JSP , all the objects like request , session... are
available
> > > implicitly which you get in servlet by extending HTTPServletRequest
class. right ?
> >
> > True.
> >
> > > So why one will use Servlet with JSP? As I understand one uses Java
code in a
> > > separate bean because he/she wants to hide the business logic. Right ?
Why to keep
> > > the same code in a servlet ?
> >
> > Who told you that the same code should be in JSP and servlet as well ? I
> > didn't.
> >
> > > Is my thinking correct or am i missing here something ?
> >
> > Yes, you're almost correct:) Take a look at the series of Java code and
> > give yourself an answer on the question which one is simpler to read and
> > maintain. I think that you didn't work on large project(s) which use
> > loads of JSP, Servlets and (probably) EJBs. In such projects, you
> > wouldn't be able to write all the code because of time you would spend
> > on it. Another aspect is knowledge you could bring to a project. One is
> > very familiar with HTML code, another with JSP Tags, and another with
> > servlets, yet another with EJB and so on. Having such people in one
> > place, you could start coding without a need to infere with each other.
> > Everybody could work in his/her own way and during last days of
> > development all the code could be bring together and it should work. Of
> > course, you would have to define objects which could fly from one side
> > to another, but that's it, nothing more, nothing less. The best thing is
> > that you could fire one of developers and hire another one who has
> > experience in doing one thing, say, HTML+CSS+Java Script or Java
> > programming in general or JSP/Servlet programming or...
> >
> > That's not new thing in programming. The term Model-View-Controller is
> > known since the beggining of Smalltalk (actually I'm not sure about an
> > origin of that term, but I found MVC mentioned as Smalltalk's term). So,
> > what is behind MVC. If you look at Swing API, you'll see at a glance
> > that e.g. JTable is based on another class - TableModel. TableModel
> > holds a data and let you manipulate that. If that data needs to be
> > displayed, you should construct a table with a model as just mentioned
> > TableModel. It's very simplified model, but your should get a clue:)
> >
> > Let see some examples, so you'll get more feeling about JSP and how one
> > can mess it up.
> >
> > 1. First example where you see some JSP and HTML code in one file (very
> > bad design):
> >
> > <html>
> > <body>
> > <table>
> > <%
> > // Vector of Men
> > Vector v = getSomeDataFromSomewhere();
> > for (Enumeration e = v.elements(); e.hasMoreElements(); ) {
> > Man m = (Man)e.nextElement();
> > String firstName = m.getFirstName();
> > String lastName = m.getLastName();
> > %>
> > <tr>
> > <td><%= firstName %></td><td><%= lastName %></td>
> > </tr>
> > <%
> > }
> > %>
> > </table>
> > </body>
> > </html>
> >
> > 2. Second example where you see only HTML code with some new tags
> >
> > <%@ taglib uri="/tags" prefix="my" %>
> > <html>
> > <body>
> > <table>
> > <my:show name="man">
> > <tr>
> > <td><jsp:getProperty name="man" property="firstName"></td>
> > <td><jsp:getProperty name="man" property="lastName"></td>
> > </tr>
> > </my:show>
> > </table>
> > </body>
> > </html>
> >
> > Now, it's time to answer some questions:
> >
> > 1. How do you fell how much time HTML guru will have to spend to learn
> > 1st and 2nd example ?
> > 2. What about (cheap) HTML editors with some fancy coloring stuff ? Do
> > they know about JSP tags ?
> > 3. Which parts of file can be changed and what the impact is thereafter
> > ?
> > 4. Do you see that 2nd example is divided, so JSP stuff is done by JSP
> > guru and the another by HTML guru. They can work separately. Just give
> > specification about new tags to HTML developer and you can change Java
> > code with no impact on HTML presentation.
> >
> > I hope it's not too long and it's easy to read and understand:)
> >
> > >
> > > Thx in advance
> > > Rakesh.
> >
> > Jacek Laskowski
> >
> >
===========================================================================
> > To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
JSP-INTEREST".
> > Some relevant FAQs on JSP/Servlets can be found at:
> >
> > http://java.sun.com/products/jsp/faq.html
> > http://www.esperanto.org.nz/jsp/jspfaq.html
> > http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> > http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
>
>
===========================================================================
> To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
JSP-INTEREST".
> Some relevant FAQs on JSP/Servlets can be found at:
>
> http://java.sun.com/products/jsp/faq.html
> http://www.esperanto.org.nz/jsp/jspfaq.html
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
===========================================================================
To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST".
Some relevant FAQs on JSP/Servlets can be found at:
http://java.sun.com/products/jsp/faq.html
http://www.esperanto.org.nz/jsp/jspfaq.html
http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
