Actually, here's what I do: I have a Singleton Hashtable "Cache" class that I wrote, it holds the Templates, not the Transformers. In such a case you can get a transformer from the template instance in the cache without needing to read the xsl file again. When you don't find the template in the cache then you can stick a new instance in.
-M. Mark R. Diggory wrote: > Put it in the "ServletContext", then its available to all Sessions and > Servlets across the application. > > Are jaxp Transformers syncronized at all? If so, couldn't different > sessions grab the same transformer from the context and use it? > > -M. > > neal wrote: > >> Actually, >> >> Isn't the SessionContext analogous to the session object in JSP? If I >> were >> to place the Transfomer object in their for cache it would be tied to a >> specific user and I would have to hold numerous copies of it >> simultaneouly >> whether they were in use or not. Seems like this would eat up a lot of >> resources. >> >> As for what I am currently trying to do ... I just created a single >> Hashtable which should be available to the entire application (all >> servlets) >> and it contains the Transformer objects for each XSLT. My plan was >> to have >> the servlet make a copy of one of these Transformer objects as needed >> and >> perform a >> transform and then destroy the copy, while the original would stay in >> cache >> in the Hashtable. I thought this way I could reduce the overhead of >> having >> to (a) read from disk and (b) parse the file into a DOM-like >> structure each >> time. >> >> It does not appear however that I can make a copy of a Transformer >> object >> however since it does not appear to implement the Cloneable >> interface. Is >> it just me or is this a significant limitation of Java ... that you >> can't >> make byVal copies of objects at will? SO frustrating!!! >> >> Can anyone make a suggestion for caching my XSLTs? >> >> Thanks. >> Neal >> >> >> -----Original Message----- >> From: Shannon Lal [mailto:[EMAIL PROTECTED]] >> Sent: Wednesday, September 18, 2002 6:34 AM >> To: [EMAIL PROTECTED] >> Subject: RE: Caching / Cloning >> >> >> Neal, >> Have you thought about using SessionContext. I believe the session >> context >> is specific to the session of the servlet, so when the instance of the >> servlet is run, it will have it s own copy of its Transforms to work >> with. >> That way you don t have to worry about different servlet instances >> locking >> of data. >> >> OR >> Are is the Transforms hashtable shared by all servlet instances. If so >> e-mail with more information about what you are doing and I can give you >> some more information. >> >> Nin >> >> >> >> >>> From: "neal" <[EMAIL PROTECTED]> >>> Reply-To: "Tomcat Users List" <[EMAIL PROTECTED]> >>> To: "Tomcat Users List" <[EMAIL PROTECTED]> >>> Subject: RE: Caching / Cloning >>> Date: Tue, 17 Sep 2002 22:35:55 -0700 >>> >>> Siddarth, >>> >>> Thanks but I'm thinking of two possible issues: >>> >>> 1. using the ServletContext.getContext() - won't this still just >>> return a >>> pointer rather than cloning the cache? I looked at the API and >>> didn't see >>> anything that said it was copying the object and creating a local copy. >>> >>> 2. Returning and having to handle the entire contents of the servlet >>> context >>> could imply alot of overheard, I would think....at least presuming your >>> copying the context each time a page is called in ordert to obtain a >>> local >>> copy of something, in this case an XsLT Transformer object. >>> >>> Am I misunderstanding your suggestion, or how this would work? >>> >>> Thanks. >>> Neal >>> >>> >>> -----Original Message----- >>> From: Siddharth [mailto:[EMAIL PROTECTED]] >>> Sent: Tuesday, September 17, 2002 10:30 PM >>> To: Tomcat Users List >>> Subject: Re: Caching / Cloning >>> >>> >>> Neal, >>> I have never worked with XSLT but I can show you the way where you >>> can have >>> an >>> initial copy of ServletContext which you can use independently. >>> Interface ServletContext has a mathod called >>> getContext(java.lang.String uripath) returns ServletContext >>> You can use this method by giving uripath of same application to get >>> a copy >>> of cache. >>> >>> I hope, This suggestion may help you. >>> Siddharth >>> >>> >>> ----- Original Message ----- >>> From: neal <[EMAIL PROTECTED]> >>> To: Tomcat Users List <[EMAIL PROTECTED]> >>> Sent: Wednesday, September 18, 2002 9:52 AM >>> Subject: Caching / Cloning >>> >>> >>> >>> >>>> Is there a way to make a copy of what's in my cache >>>> >>> >>> (getServletContext()) >>> >>> >>>> and make changes to that local copy, independent of whether the cached >>>> object implements Cloneable()? >>>> >>>> >>>> In order to speed up my XSLT I thought I would preload them (their >>>> Transformer objects) into app scope and simply retrieve it as >>>> needed for >>>> transforms. >>>> >>>> This works fine except I just remembered that I need to set attributes >>>> >>> >>> on >>> >>> >>>> these XsLT Transformer objects. Now, I am PRESUMING that this means >>>> >>> >>> that >>> I >>> >>> >>>> would then be locking up the servlet context each time I set one of >>>> >>> >>> these >>> >>> >>>> parameters so then it seems I should clone() the object locally. That >>>> >>> >>> way >>> I >>> >>> >>>> could set the params locally without affecting (or locking) the cached >>>> version). BUT Transfomer does not appear to implement the Cloneable() >>>> interface. >>>> >>>> Is there a way around this? Am I by any chance wrong about what's >>>> >>> >>> actually >>> >>> >>>> happening here? Can anyone make a suggestion? >>>> >>>> Here's what I'm doing basically: >>>> >>>> ServletContext application = getServletContext(); >>>> application.setAttribute("TEMPLATES_HASH",templates); >>>> (where templates is a Hashtable containing Transformer objects) >>>> >>>> >>>> Thanks. >>>> Neal >>>> >>>> >>>> -- >>>> To unsubscribe, e-mail: >>>> >>> >>> <mailto:[EMAIL PROTECTED]> >>> >>> >>>> For additional commands, e-mail: >>>> >>> >>> <mailto:[EMAIL PROTECTED]> >>> >>> >>> -- >>> To unsubscribe, e-mail: >>> <mailto:[EMAIL PROTECTED]> >>> For additional commands, e-mail: >>> <mailto:[EMAIL PROTECTED]> >>> >>> >>> -- >>> To unsubscribe, e-mail: >>> <mailto:[EMAIL PROTECTED]> >>> For additional commands, e-mail: >>> <mailto:[EMAIL PROTECTED]> >>> >> >> >> >> >> >> _________________________________________________________________ >> Send and receive Hotmail on your mobile device: http://mobile.msn.com >> >> >> -- >> To unsubscribe, e-mail: >> <mailto:[EMAIL PROTECTED]> >> For additional commands, e-mail: >> <mailto:[EMAIL PROTECTED]> >> >> >> -- >> To unsubscribe, e-mail: >> <mailto:[EMAIL PROTECTED]> >> For additional commands, e-mail: >> <mailto:[EMAIL PROTECTED]> >> >> >> > > > > > > -- > To unsubscribe, e-mail: > <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: > <mailto:[EMAIL PROTECTED]> > -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
