ActionServlet is like BackBone of our application, we have done all actions(request & response) by using only one instance, that is ActionServlet's Instance, that is the main reason to go for MVC architecture, no need to create more than one instance, thats why we use only one ActionServlet for whole project.
In Previous Structure, we should create new instance for each and every request, in MVC no need.
Note of it "we have only one Backbone in our BODY"
The ActionServlet is the Controller comonent that handle the client request and determines which Action class will process each received request. As in MVC2 architecture only one controller component should govern the flow of application -i mean when request is generated ,it should be served by action class and based on the outcome next view is selected (internally RequestDispatcher forward() method is used to choose next view). All business logic is executed by Action class ,so ActionServlet does not have such overhead that we need multiple instances .
he Jakarta Struts Framework does not support configuring more than one Struts ActionServlet in the Web deployment descriptor. This limitation occurs because there is only one servlet context per Web application and the commons digester imports the Struts configuration into the servlet context. Struts stores the required information as attributes in the servlet context, and the information is retrieved by using globally defined key names. Struts will suffix these attribute names with the prefix of the Struts modules, so several Struts modules are supported in a single Web application, but multiple Struts applications are not.
