The Web container is responsible for managing the servlet�s life cycle. The Web container creates an instance of the servlet and then the container calls the init() method. At the completion of the init() method the servlet is in ready state to service requests from clients. The container calls the servlet�s service() method for handling each request by spawning a new
thread for each request from the Web container�s thread pool. Before destroying the instance the container will call the destroy() method. After destroy() the servlet becomes the potential candidate for garbage collection.
State chart diagram
http://www.jguru.se/jguru/Channel_Html/generic/images/developers/servlet_lifecycle.gif
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