Servlet Container

[Vimal Bharathi Andiappan]

When we call a new servlet it will create an instance and service to the user. Then another user can call the same servlet it wont create the new instance, but give the service from already created instance. My question was how it works and how it does the service.

[sudhir nim]

In this case the previously instantiated instance of the servlet class is used. container calls the service method in new request thread. service method processes the request and generate the response.

[Gopikrishna Kunisetty]

The Process goes like this:
1. When user initiates a request, the servlet container tries to map the request with servlet that are declared in the Deployment descriptor.
2. Once the container identifies the required servlet, it will create an instance of that servlet.
3. Once the instance is ready, the container allocates a thread for the request and calls the service() method of the servlet, passing the request and response objects as arguements..
4. The service() methods takes care of invocation of http method. (i.e, GET, POST etc..)
5. After completing the service the container removes the thread or moves it to the container-manged thread pool.

Here you have to observe that, each request will run in separate thread and only one instance of servlet will be created per JVM.

[Gaurav Agarwal]

As Krishna stated only one instance is created and all the upcoming request is handled by different thread which is done by calling run() method and it is a servlet container responsibility to manage the thread for each request.

Hope this clerify your concept