Hi Tim. Help me out here 'cause I don't understand what problem you see with storing a value in a static field?
As far as I know (and I am limiting my discussion here to Java and servlets) objects are not persisted across http requests unless they are serializable and stored in session or in memcache and that takes programming effort meaning you have to deliberately program the behavior. Yes there are statefull web frameworks such as Wicket and JSF for instance that will persist objects accross requests without programming effort but even these are limited to model and view class instances for the most part. As for classes (not instances) persisting across requests (and eliminating those classes that are servlet and other server pluming classes) what classes are persisted across requests? If storing values in class static fields were problematic I'd guess that this would break quite a number of web apps. What do you think? Jeff On Thu, Jul 29, 2010 at 7:31 AM, Tim Hoffman <zutes...@gmail.com> wrote: > The biggest problem I see with storing the value at a class/module > level > is you really need to make sure you clean up after yourself, otherwise > the > value may still be set when the next request is processed and that > value may not be > appropriate. > > I would personally always grab/cache values in request object, > memcache, and or session > as appropriate. > > That way there is no danger of exposing data to other requests. > > But hey, if you want to use module level caches go for it. > > I have been running appengine projects ever since it was released and > started out with some > module level cache, and regretted it ever since. It was has proven to > be difficult ensure the cache > has been cleaned up, where as memcahce you can control out of > process. (You can't shut an instance down > if it has an error and you can't remove a value from a module cache) > > Rgds > > T > > On Jul 29, 4:19 pm, Bill Edwards <twmaf...@gmail.com> wrote: > > Hey guys, > > > > Is it horrible to use global variables? I am currently executing a > > query at the beginning of my handler and storing the query result > > within class object A. I subsequently need to access the query result > > within multiple different class objects, say B, C, and D. It has been > > recommended to me to cache object A in the request object, but i need > > to access the variable from within various class objects, so I'm > > finding that I have to pass the object A in to the constructor for > > every new object i define, and then sync any changed state of object A > > with the handler's version of object A when the various class object > > functions are completed. > > > > So it really seems like the simplest way to do things is to just > > define a global variable. Is there a better option? Can I think I > > would ideally want to create something liek a session object to store > > the global object. > > > > Thanks! > > Bill > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to google-appeng...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine+unsubscr...@googlegroups.com<google-appengine%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- -- Jeff -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appeng...@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
