Hi On Jul 29, 8:40 pm, Jeff Schwartz <jefftschwa...@gmail.com> wrote: > Hi Tim. > > Help me out here 'cause I don't understand what problem you see with storing > a value in a static field?
Wouldn't have a clue. I don't use java on appengine. You didn't mention in your original post you where specifically talking about java. In python class/module cached definitions last for as long as the app instance is running. T > > 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%2Bunsubscrib > > e...@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.
