After having worked with Swing very long I want to add that object creation might be a performance problem in the Swing framework, but given the time a request/response cycle takes in web-engineering anyways it is by far preferable to have request beans in usual situations.
You need some overhead for the request/response-cycle which you can usually neglect, but the costs in server memory for session beans might not be negligible. regards, Martin On Fri, 11 Feb 2005 14:18:49 +0100, Matthias Wessendorf <[EMAIL PROTECTED]> wrote: > Sean, > > thanks for your replay > > Sean Schofield wrote: > > Matthias, > > > > Its true that object creation can be expensive but you also have to > > consider how often the underlying data (assuming it comes from a > > database) changes. In Struts you have ActionForms which are > > essentially request scope beans (similar to but not the same as > > backing beans). Its no big deal constantly creating these every > > sure not similar, since backing beans has more *features* > as only being a "form-bean". Btw. scope attribute's value > of <action/> is "session" as default. > > > request. > > > > You also want to consider that session beans take up server memory. > > If you have ten different backing beans for ten different pages you > > will have ten beans sitting around in memory for each user that goes > > through those ten pages (until the session expires.) > > ah, yes good point! thanks. > > > In my application we are going to have to use a lot of request scope > > beans beacause the data needs to be up to date. It can be changed by > > That is also the thing that I wanted to do! But my co-worker said: > "make them to session, sicne creation is VERY expensive" > > --> reason for my mail > > > other users at any time, so we want to show the latest on every > > request. In theory you could have a session bean to avoid recreating > > the object and use a scheme to repopulate it but I am not wild about > > that. > > Ok, thanks! > > I remember that Craig also allways mentioned request instead of session, > but couldn't find a thread on that... > > -Matthias > > > > Anyways that is my .02, > > > > sean > > > > > > On Fri, 11 Feb 2005 11:35:16 +0100, Matthias Wessendorf > > <[EMAIL PROTECTED]> wrote: > > > >>Hi all, > >> > >>I am just on reading [1]. There is mentioned, that > >>object creation is very expensive and you should better > >>reuse objects instead of creating them often. > >> > >>Now I thought about scope of my backing beans. > >>What should be better request or session? > >> > >>If I have request scoped backing beans that > >>get often created by ONE user and I have MANY > >>users... will request scope slow down my web app? > >> > >>Ok... application is also there, but that is > >>an other stage :-) I would use such a backing > >>bean only for *knowing* about ALL users logged > >>into the application. > >> > >>[1] http://www.oreilly.com/catalog/javapt/chapter/ch04.html > >> > >> > >>-Matthias > >> > > > > > > -- > Matthias We�endorf > Aechterhoek 18 > DE-48282 Emsdetten > Germany > phone: +49-2572-9170275 > cell phone: +49-179-1118979 > email: matzew AT apache DOT org > url: http://www.wessendorf.net > callto://mwessendorf (Skype) > icq: 47016183 > > -- > Matthias We�endorf > Aechterhoek 18 > DE-48282 Emsdetten > Germany > phone: +49-2572-9170275 > cell phone: +49-179-1118979 > email: matzew AT apache DOT org > url: http://www.wessendorf.net > callto://mwessendorf (Skype) > icq: 47016183 >
