u welcome :-) L On 1/2/07, Daniel Chacón Sánchez <[EMAIL PROTECTED]> wrote:
Thanks Leon!!!, I got it!!!2007/1/2, Leon Rosenberg <[EMAIL PROTECTED]>: > > On 1/2/07, Daniel Chacón Sánchez <[EMAIL PROTECTED]> wrote: > > Thanks > > > > Leon, about using the servlet context, I read that on a distributed > > application the share information of the servlet context is not > entererly > > global right?: > > Right, but since the data is readonly its ok to have a copy per > webserver, right? It doesn't harm you to put one data-object (even a > complex one) in the application scope. If you need to check for > updates periodically you could make use of the subject-observer > pattern and notify the webservers from the business layer via > rmi/corba/jms/whatever to renew their data or just check if the data > is still valid and replace it if needed periodically in a separate > daemon thread. > > > > > *"...In the case of a web application marked "distributed" in its > deployment > > descriptor, there will be one context instance for each virtual machine. > In > > this situation, the context cannot be used as a location to share global > > information (because the information won't be truly global). Use an > external > > resource like a database instead."* > > > > > > About the second solution that you gave to me, I do not understand, you > said > > that for example in my BaseAction Class create a method to put the > objects > > in the request? The problem is that in every request the application > will go > > to the database to load the objects and then put them on the request! > What I > > do not understand is how to put the objects in the request without have > to > > go the database each time that a request is made and the method in the > > BaseAction is call. > > BaseAction extends Action{ > private static Data1Class data1; > private static Data2Class data2; > .... > > static{ > data1 = createData1FromDB(); > data2 = createData2FromDB(); > } > > //now in my actions i have my own execute method, you may have > something //similar: > protected void preProcessExecute( > ActionMapping mapping, > ActionForm af, > HttpServletRequest req, > HttpServletResponse res) > throws Exception{ > > req.setAttribute("data1", data1); > req.setAttribute("data2", data2); > ......... > } > > protected void postProcessExecute( > ActionMapping mapping, > ActionForm af, > HttpServletRequest req, > HttpServletResponse res) > throws Exception{ > > } > > public abstract ActionForward myExecute( > ActionMapping mapping, > ActionForm af, > HttpServletRequest req, > HttpServletResponse res) > throws Exception; > > > public final ActionForward execute( > ActionMapping mapping, > ActionForm bean, > HttpServletRequest req, > HttpServletResponse res) > throws Exception { > > > preProcessExecute(mapping, bean, req, res); > ActionForward forward = myExecute(mapping, bean, req, > res); > postProcessExecute(mapping, bean, req, res); > return forward; > } > } > > You just have to ensure, that when an Action overwrites preProcess it > calls super.preProcess. > The advantage of this method is, that actions at the end of the > hierarchy have a chance to overwrite the data by the base action, > which is quite useful for internationalization and such. > > Same rules for updates as for servletContext apply. > > regards > Leon > > > > > > 2007/1/2, Leon Rosenberg <[EMAIL PROTECTED]>: > > > > > > The easiest way is to initialize the data once in the > > > init(ServletConfig) method of the servlet and put them into the > > > application scope (servletcontext). The struts tags will be able to > > > access the data directly, so you don't need to change a bit. > > > Of course the data structures theirself must be threadsafe to access, > > > which shouldn't be a problem if you are only reading them. > > > > > > Alternatively you can perform this in a static initializer in a action > > > and put them in the request scope of each request (if you have a > > > common code block all actions are passing through, like authorization) > > > or into the application scope on first request (which would need a bit > > > of synchronization with double checked locking) > > > > > > regards > > > leon > > > > > > On 1/2/07, Daniel Chacón Sánchez <[EMAIL PROTECTED]> wrote: > > > > Hi all, I'm using struts framework on my application, but I have a > > > > perfomance question. > > > > > > > > When my application starts I load objects in session that may or may > not > > > > will be used (depends on what the user does), for example I load > the > > > health > > > > centers, hospitals, countries, etc, that will be available for the > users > > > in > > > > html:selects, I know that to had many objects in session is not > good, in > > > > fact each time the user click on one application option (menu) all > the > > > > objects in session are erased, except the ones that I load on the > start > > > of > > > > the application. Is there a way (maybe a pattern) to load this > objects > > > in > > > > the moment that are needed, and not load all at the start of the > > > > application. This object are use on differents modules so I load > them on > > > the > > > > start of the aplication and put them in sesion for not to go to the > > > database > > > > each time I need to load them on a html:select. > > > > > > > > any solution, idea? or that is the only way? > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
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