I just committed an update to this to remove the static DatastoreService instance.
Vince On Sat, Oct 31, 2009 at 2:08 PM, Vince Bonfanti <vbonfa...@gmail.com> wrote: > This looked like an interesting problem, and I already had most of the > pieces in place, so here's my first attempt, which is implemented in a > single class (also attached, along with some test files): > > > http://code.google.com/p/gaevfs/source/browse/trunk/src/com/newatlanta/appengine/taskqueue/Deferred.java > > I'm more than happy to contribute this for inclusion in the SDK. > > Some caveats: > > 1) Because of issue #2097 > (http://code.google.com/p/googleappengine/issues/detail?id=2097), this > doesn't work on the development server (it does work in production). > So go star that issue! > > 2) I've only done minimal testing on the production server (see the > attached test files). > > 3) This post is the only documentation that's currently available. > > First, add the following your your web.xml: > > <servlet> > <servlet-name>Deferred</servlet-name> > > <servlet-class>com.newatlanta.appengine.taskqueue.Deferred</servlet-class> > </servlet> > <servlet-mapping> > <servlet-name>Deferred</servlet-name> > <url-pattern>/_ah/queue/deferred</url-pattern> > </servlet-mapping> > > Second, define the "deferred" queue within queue.xml (use whatever > rate you want): > > <queue> > <name>deferred</name> > <rate>10/s</rate> > </queue> > > Next, create a class that implements the > com.newatlanta.appengine.taskqueue.Deferred.Deferrable interface; the > "doTask()" method of this class is where you implement your task > logic. > > Then, invoke the com.newatlanta.appengine.taskqueue.Deferred.defer() > method to queue up your task: > > TestDeferred testDeferred = new TestDeferred(); // implements Deferrable > Deferred.defer( testDeferred, "one", "two", "three", 1, 2, 3 ); > > (Note that it would be possible to pass arguments as attributes to > your Deferrable instance, rather than using varargs; I'm not sure it > makes much difference which you choose). > > Just as for the Python implementation, if the arguments size exceeds > 10KB, the arguments are stored in a datastore entity, which is then > deleted when the task is executed. Also, your doTask() method can > throw a PermanentTaskFailure exception to halt retries; any other > exceptions cause the task to be retried. > > Let me know if you find this useful, have any questions or encounter > any problems. > > Vince > > On Fri, Oct 30, 2009 at 6:13 PM, Jason (Google) <apija...@google.com> wrote: >> Hi David. This may be coming to Java eventually, but it hasn't been started >> yet. If you or anyone else is interested in contributing, let me know. >> >> - Jason >> >> On Wed, Oct 28, 2009 at 7:52 AM, David Chandler <turboman...@gmail.com> >> wrote: >>> >>> Re: http://code.google.com/appengine/articles/deferred.html >>> >>> Will this be coming to AppEngine for Java? >>> >>> David Chandler >>> http://turbomanage.wordpress.com >>> >>> >> >> >> >> >> > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~----------~----~----~----~------~----~------~--~---
