Change jar class dynamically?

Hi all

I have a jar file which content must be changed dynamically. For example in my project there are some jar files which must be changed in development and production environment. i.e jar is created with production set of classes , but in development ( or simulation ) process we changed some classes inside that jar ( by replacing with dummy set of classes which only do logging ). How can i achieve this using gradle ?

So simply is there a way to change a jar classes after it’s been created ?

I found a way to do this by using ant tasks. i.e extract jar and re-create using different set of classes.