First, init method is a call back method of a server. so, you dont have control on it. but in most of the container, you can ask server to start init method by requesting a servlet or at the time of starting a web application using load-on-startup tag .
Joined: Jun 02, 2011
calling the init method depends on the server and its configuration. it can be when -
server start or server get the first request. It is right
Called by the servlet container to indicate to a servlet that the servlet is being placed into service.
The servlet container calls the init method exactly once after instantiating the servlet. The init method must complete successfully before the servlet can receive any requests.