Inject Object on deployed REST service

Inject Object on deployed REST service

I'm developing a REST API in an Osgi bundle. I'm using Jersey to deploy
the services into a jetty container with a javax servlet for each class
with REST services.
Each class has an attribute like this
Private DBInterface dbInterface;
With setters and getters, and I need to inject the object from another
bundle once the service is deploy (in runtime). So anyone know a way to do
it?
Thanks in advance.
PD: I'd like to do it without declaring the service as singleton so every
REST request is answered from another instance of the service (actual
stateless REST)