Re: freemarker plus javarebel problems...caching?

It does caching, and you wouldn't want to turn it off, because that'd  
force class introspection on each access, and it'd kill performance.

The class introspection is managed by BeansWrapper, in  
introspectClass() method. It has means to detect reloaded classes;  
namely if it sees a class that has the same name as an already cached  
one, but its identity is different, it will clear the cache. It will  
also log an INFO message in the "freemarker.beans" log category saying  
"Detected a reloaded class [com.mycompany.SomeClass]. Clearing  
BeansWrapper caches."

And anyway, our introspection cache data is bound to Class object  
identity, not its name (the name is just used as a check to detect  
class reloading). When you reload classes, the newly loaded Class  
objects have different identity, and will thus be inspected separately.

So, in a nutshell, it should be able to detect that class reloading  
happened, and should clear its cache when it does... If you can afford  
to do some debugging in BeansWrapper.introspectClassInternal(), you  
could maybe spot what's wrong. I.e. when you reload classes, only  
newly created instances of the class will be of the reloaded class -  
already existing object instances will remain of their original, old  
class; maybe you're still holding references to your old objects?

As an alternative workaround, you could just create a new instance of  
BeansWrapper whenever you yourself detect class reloading, and pass it  
to Configuration.setObjectWrapper(). That way the newly created  
BeansWrapper will have no caches and will set out to introspect all  
classes anew. But that really shouldn't be necessary -- as I said, we  
did anticipate class reloading in FreeMarker (and anyway, we cache  
based on identity of Class objects, not their name).

Attila.

--
home: http://www.szegedi.org
weblog: http://constc.blogspot.com

On 2008.05.14., at 21:26, Jonathan Chase wrote:

> I'm trying to use JavaRebel (http://www.zeroturnaround.com/ 
> javarebel/) in my Spring MVC app...everything in pretty vanilla, and  
> JavaRebel is correctly reloading class file changes.
>
> However, I've noticed that when I add a new method to a class,  
> FreeMarker doesn't find it (until I restart the JVM).
>
> Is FreeMarker doing some sort of caching of class metadata?  If so,  
> is there a way to turn that off so that it will pick up the changes  
> in the class files?
>
> Thanks!
> Jon






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