I'm using AEM 6.4,
I want to call a servlet from a Model class,
What is the way to do that?
AEM - Questions
Why do you want to call servlet from Sling model, what is your requirement?
Other way around i.e. Sling Model Adaptation is possible Performing Sling Model Adaptation Using Request and Resource Objects
to me via the httpclient, you can fire http-calls.
As Feike mentions - use Java HTTPClient API as discussed here - Adobe Experience Manager Help | Invoking Adobe Experience Manager Sling Servlets using Apache HTTP A...