Thanks for a most illuminating discussion. I would be very interested to
have a copy of your framework.
Chris Walker
Brainbench MVP for ASP
http://www.brainbench.com
> -----Original Message-----
> From: Duffey, Kevin [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, November 21, 2000 2:35 AM
> To: [EMAIL PROTECTED]
> Subject: Re: setItem vs request/session (redirected)
>
>
> Ahh the Model 1, Model 1.5 and Model 2 debate. I know it
> well. I used to be
> a Model 1.5 developer. Here are some of the differences:
>
> Model 1:
> All code is in the JSP page. You use JSP pages with code
> and submit to JSP
> pages with code. You do logic, etc in your JSP page.
>
> Model 1.5:
> Most code is in a javabean that your JSP page uses. When
> you submit a
> form, you submit it "back" to the JSP page, which has a
> scriplet that then
> determines if its a form submission..or the first time its
> being executed.
> If its not the first time..it must be a form being
> submitted..so it calls a
> javabean method passing in request, response, session, etc so that the
> javabean method does the logic.
>
> Model 2:
> All JSP pages have very little scriplet code. They use path
> mapping or
> extension mapping to direct all submissions to a single
> controller servlet.
> That single point of entry can then direct to any number of classes
> depending on the "command" being passed in. This often
> follows a true MVC
> model, and usually requires a command pattern to be used
> properly (which
> allows the controller servlet to determine what class to call
> to handle the
> request).
>
>
> Strengths/Weaknesses:
>
> Model 1:
> Strength: Very easy to implement, initially requires "no brainer"
> knowledge of JSP and Java.
> Weakness: Very quickly becomes a mess. It is quite like
> using Servlets to
> return your HTML, but in the opposite end of the spectrum.
> Instead of code
> with HTML in it, you now have HTML with code in it. It is
> ugly to work with
> and difficult to maintain..especially because most people
> don't comment
> their code, even more so in JSP pages.
>
> Model 1.5:
> Strength: Much like Model 1..very easy to implement, so its fast to
> prototype pages and functionality. Better than Model 1 because it now
> removes alot of "logic" code out of JSP pages and puts it
> into JavaBeans.
> Weakness: Still uses a bit of java code in JSP and
> requires forms/links
> to be submitted to itself for processing (or to another JSP
> page that then
> calls the bean..which results in more coding). Much like
> Model 1, it can get
> ugly as you add more JSP scriplet code. It doesn't cleanly
> separate the VIEW
> from the CONTROLLER in the MVC approach.
>
> Model 2:
> Strength: Cleanly separates Java controlling code from jsp
> pages (and
> javabeans). It allows a javabean to be the "model" of the
> users state (think
> of wizards..multiple pages to build up a single transaction..using a
> javabean you can store the state of that user as he/she
> progresses through
> the pages. You can do this with the other models too..but
> this cleanly leave
> the javabean to just storing the state..no logic code that
> jsp pages call).
> It also does something the others don't do (they can..but its
> more work..and
> it involves putting "logic" in the jsp page). It allows a
> single point of
> entry for all requests (as long as they all use the mapping
> that calls the
> controller servlet). Because of this, you can put security
> measures in your
> controller servlet, such as making sure if a user tries to
> access a specific
> page (via the url they are going to), they have proper
> permission to do so.
> More so, this approach allows very easy scalability that the other two
> approaches don't do very well. Even better..for a developer it is much
> easier to maintain coming in to a project.
> Weakness: More difficult to implement (from scratch), more
> work to add
> functionality. Requires more "knowledge" of servlets, jsps,
> javabeans and
> the MVC paradigm.
>
> So let me divulge a bit on why Model 2 is the MVC of choice!
> First..and
> foremost, it "usually" requires more work. I say usually
> because if you were
> to do it from scratch, you would have to write the controller
> servlet, the
> framework for calling the right classes, etc. However, it
> just so happens
> that this stuff has been around for a while, so there are
> alot of already
> pre-built frameworks you can use. If you go to
> jakarta.apache.org, and go to
> the Struts link, Struts is one. Its an OpenSource project
> that incorporates
> a whole hell of a lot! The only down side to using Struts..is
> if you want to
> keep "current" with it, you can't modify the source
> yourself..the later
> versions will undo what you did..so you would have to apply
> them every time.
> On the other hand..I decided to write one myself, that is
> very short, only 5
> classes, and you can modify the source all you want. Ideally,
> you want to
> modify the Controller Servlet to include your security
> measures. I didn't
> write mine in such a way that it calls any "hooks" that you
> can override,
> but because I offer my code free, you can modify it all you want. My
> framework is much like Struts, only that Struts provides a
> nice ability to
> load a single action.xml file that contains all the action names and
> mappings, where as my mappings are contained in the
> ControllerServlet in
> code.
>
> At any rate..I gotta get back to work..so grab Struts, look at the
> documentation..it has very good docs on how to use it. If you
> like it..use
> it..its free. It does require a Servlet 2.2 engine however,
> which is a J2EE
> move. If your using an older Servlet 2.1 engine, my framework
> will work
> fine. My framework is a bit faster than Struts, but Struts offers
> international abilities, the single xml config file, etc. Another nice
> feature of Struts is auto-bean population. You specify a
> javabean that a JSP
> page will use, and upon submitting the form, it
> auto-populates the bean with
> form element names from the form submitted if they match the
> methods..just
> like using the <jsp:setProperty property="*" /> call on JSP
> pages. Only, the
> downside to Struts is that EVERY SINGLE SUBMISSION tries to
> auto-populate a
> bean. My framework gets rid of that problem and only
> populates a bean if you
> supply a auto-populate=true request parameter. I also use a simple
> reflection technique to call a method directly in an action
> class, whereas
> Struts requires you to have a bit longer perform() method
> that returns a
> mapping object and so on.
>
> So read up on the docs of Struts, tell me if you want my
> framework..and let
> me know what you think. Lastly..I will say this..even though
> Model 1 and
> Model 1.5 are "fast" to prototype, with my framework (and
> Struts) its much
> faster! Because all the work is done in setting up the mapping, the
> "default" logic, etc..you simply add a JSP page with HTML in
> it (and you use
> a javabean to "get" the form state info for the form
> elements), create an
> action class and add a mapping. I can create a new area of
> functionality
> with my framework in a matter of minutes. The page may not do anything
> initially..but it is very fast. You create a JSP page (or
> more), a JavaBean
> that will hold the state, a mapping in the ControllerServlet,
> and an action
> class with one method per "action" you want your page(s) to
> take based on
> the user buttons clicked.
>
> Hope that helps.
>
>
>
> > -----Original Message-----
> > From: dion [mailto:[EMAIL PROTECTED]]
> > Sent: Friday, November 17, 2000 5:45 AM
> > To: [EMAIL PROTECTED]
> > Subject: setItem vs request/session
> >
> >
> > Hello all,
> >
> > I noticed that some jsp application use 2 (or more) different
> > approach when executing some of the business process :
> > one by using httpservletrequest, httpservletsession,
> > another by using setItem then call the javabean's method via JSP
> > (please see code below).
> >
> > my question is, what's the strength (and weakness) of each
> > approach, especially for mission-critical application?
> > i've seen a couple of books, and not many cover this, could you
> > point me to any available resources?
> >
> > thank's a lot!
> >
> > // login.jsp (login form)
> > <form action="loginprocess.jsp">
> > userid : <input type="text" name="userid"> <br>
> > password : <input type="password" name="password"> <br>
> > <input type="submit">
> > </form>
> >
> > -----
> >
> > // loginprocess1.jsp (using httpservletrequest,
> httpservletsession)
> > <jsp:useBean id="mybean" scope="session" class="com.dion.Login"/>
> >
> > <%
> > // getParameter & checkhappens inside the the bean
> > session = mybean.processRequest(request, session);
> > %>
> >
> > loginis = <%= session.getAttribute("islogin") %>
> > privelege = <%= session.getAttribute("privelege") %>
> >
> > ----
> >
> > // loginprocess2.jsp (using javabeans to fill the
> > properties, do the
> > // next step inside the jsp)
> > <jsp:useBean id="mybean" scope="session" class="com.dion.Login"/>
> > <jsp:setProperty name="mybean" value="*"/>
> >
> > <%
> > String islogin = mybean.CheckLogin();
> > String privelege = mybean.CheckPrivelege();
> > %>
> >
> > loginis = <%= session.getAttribute("islogin") %>
> > privelege = <%= session.getAttribute("privelege") %>
> >
> >
> >
> > --
> > Best regards,
> > dion mailto:[EMAIL PROTECTED]
> >
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> > 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
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> >
>
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> Some relevant FAQs on JSP/Servlets can be found at:
>
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> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
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