Explain how servlet life cycles
The life-cycle of a typical servlet running on Tomcat

  • Tom-cat receives a request from a client through one of its connectors
  • For processing, this request Tomcat maps this request to appropriate
  • Once the request has been directed to the appropriate servlet, Tomcat verifies that servlet class has been loaded. If it is not than Tomcat wraps the servlet into Java Bytecode, that is executable by the JVM and forms an instance of the servlet
  • Tomcat initiates the servlet by calling its init The servlet contains code that is able to screen Tomcat configuration files and act accordingly, as well as declare any resources it might require
  • Once the servlet has been started, Tomcat can call the servlet’s service method to proceed the request
  • Tomcat and the servlet can co-ordinate or communicate through the use of listener classes during the servlet’s lifecycle, which tracks the servlet for a variety of state changes.
  • To remove the servlet, Tomcat calls the servlets destroy method.