67 How servlet program is execute without main method | Adv Java Servlet Programming Tutorial

#Advance #Java #Servlet #Programming #Tutorial | #adv java | #Que. #How #servlet #program is #executing #without #main(-) method? #Servlet #interview #question
Ans : 1) We give standalone application class directly to JVM for execution,
so main(-) method is required in that class to begin execution.

- Servlet program is not a standalone application to execute from command prompt so main(-) is not required in servlet program.

2) Servlet container executes our servlet program through life-cycle methods, since main(-) method is not a life cycle method, so main(-) method is not required in servlet program.

3) If running java application/container wants to create object of certain java class and wants to call methods on that object then there is no need of main(-) method in that class.

- Servlet container is contineously running application in server, which executes our servlet program by creating object of our class & by calling life-cycle methods on that object, so there is no need of main(-) in servlet class.

Practical Proof:
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Step 1) Open bootstrap.jar file

Step 2) Go to org.apache.catelina.startup.Bootstrap class

Step 3) Search for main() method.

- This Bootstrap.class file contains the logic in main(-) method to start the server & to activate servlet-container, jsp-container.

- Note : When life-cycle event is rised, servlet-container calls the life-cycle methods automatically but life-cycle event will not be raised by container when programmer calls life cycle methods manually.