BACK button difference between Weblogic and J2EE server

Question

          Hi Everyone,
          I have a J2EE application implemented mainly with JSP and EJB, which can run on
          both J2EE and Weblogic Servers seperately. When running on either of them, the
          server acts as both a web and application server.
          It is my understanding that it first goes to the cache in the browser when you
          try to revisit the previous page (JSP files) by clicking the BACK button in the
          browser. If the page is there, it just displays that page from the cache. If not,
          it will go to the server to retrive (execute) that page.
          When I run my application over J2EE server and try to visit the previous page
          by using the BACK button in the browser, it does this way correctly. But when
          I run my
          application over Weblogic server, it always goes to the server and execute the
          JSP file again in the server, rather than simply retriving that page from the
          cache. If your JSP file is simply doing data retriving, that is fine. But if it
          is doing data inserting, it will insert your data again. This is not good.
          I know that the Weblogic server is mainly an application server. But I am not
          sure when it acts as a web server,
          why it works differently from J2EE which also can acts as both an pplication and
          a web server. Does anyone have any ideas or suggestions about this?
          Thanks a lot.
          -John
          

Answer 1

I believe that the correct behaviour is to rerun the .jsp page unless the
          user specifically sets the header to allow the browser to cache it. That
          being said... You should never make a web application that can be broken by
          the user hitting "reload" or the browser automatically retrying. An
          application like this is very fragile and will probably break in practice.
          I suggest that you either make all your pages idempotent or you keep track
          through a hidden form field a transaction id and only allow the execution of
          any particular transaction once. As far as WebLogic not being a good web
          server, I would say that with 6.1 you get most of the management advantages
          of using a separate web server and also most of the static file performance
          you will find with apache or IIS.
          Sam
          "John Wang" <[email protected]> wrote in message
          news:[email protected]...
          >
          > Hi Bruno,
          >
          > Thank you for your prompt reply.
          >
          > I think I might not explain my problem clearly. My application
          > is in developing stage now. So we are just working on a single
          > serevr which can acts as both a web and an application server.
          > Later we are going to distribute our application into a web and an
          application
          > seperately.
          >
          > As you said, it seems that my problem is because the weblogic server is
          mainly
          > an application server and does not act as a web server very well. So if I
          distribute
          > my application into both a web and an application servers, it should be
          fine,
          > since it is ok when I run it over the J2EE server. Is this correct?
          >
          > In other words, I can say that the J2EE server is configured better in its
          role
          > as a web server than the weblogic server, isn't it?
          >
          > In addition, all my JSP files are only dealing with catching
          > data from user input and displaying data. Data inserting is done
          > by EJB and JavaBeans through the JSP files. Because those JavaBeans in the
          JSP
          > files, each time when I use the BACK button, it will invoke those
          JavaBeans and
          > EJBs through the JSP files and do things like inserting in the background.
          That
          > is what I mean in my previous message.
          >
          > Thanks.
          >
          > -John
          >
          > "Bruno" <[email protected]> wrote:
          > >
          > >Hi John,
          > >
          > >You should use a real Web Server on the front side of your application.
          > >Weblogic
          > >is mainly an application server that has to be used in middle tier. But
          > >it's not
          > >a good Web Server. Like almost all J2EE application. You should use a
          > >separate
          > >web server like apache, optimised to serve static file. Furthemore, this
          > >approach
          > >will enable you to physically separate the two servers for a better
          security.
          > >Anyway, usually jsp files are dynamic files and are not intended to be
          > >totally
          > >cached (except in special cases). I think you should just use JSP to
          > >display data.
          > >If you want to do data inserting, you should use EJB or JavaBeans for
          > >that rather
          > >than JSP.
          > >
          > >Hope it helps
          > >
          > >Regards
          > >
          > >"John Wang" <[email protected]> wrote:
          > >>
          > >>Hi Everyone,
          > >>
          > >>I have a J2EE application implemented mainly with JSP and EJB, which
          > >>can run on
          > >>both J2EE and Weblogic Servers seperately. When running on either of
          > >>them, the
          > >>server acts as both a web and application server.
          > >>
          > >>It is my understanding that it first goes to the cache in the browser
          > >>when you
          > >>try to revisit the previous page (JSP files) by clicking the BACK button
          > >>in the
          > >>browser. If the page is there, it just displays that page from the
          cache.
          > >>If not,
          > >>it will go to the server to retrive (execute) that page.
          > >>
          > >>When I run my application over J2EE server and try to visit the previous
          > >>page
          > >>by using the BACK button in the browser, it does this way correctly.
          > >>But when
          > >>I run my
          > >>application over Weblogic server, it always goes to the server and
          execute
          > >>the
          > >>JSP file again in the server, rather than simply retriving that page
          > >>from the
          > >>cache. If your JSP file is simply doing data retriving, that is fine.
          > >>But if it
          > >>is doing data inserting, it will insert your data again. This is not
          > >>good.
          > >>
          > >>I know that the Weblogic server is mainly an application server. But
          > >>I am not
          > >>sure when it acts as a web server,
          > >>why it works differently from J2EE which also can acts as both an
          pplication
          > >>and
          > >>a web server. Does anyone have any ideas or suggestions about this?
          > >>
          > >>Thanks a lot.
          > >>
          > >>-John
          > >>
          > >
          >