Servlet Life Cycle

Techopedia explains Servlet Life Cycle

The servlet life cycle is made up of four stages:

• Instantiation
• Initialization
• Client request handling
• Destruction
  

When a servlet request is mapped, the servlet container checks for the existence of a servlet class instance. If an instance does not exist, the Web container loads the servlet class, creates an instance of this class and initializes this instance by calling the init() method.

The initialization process is completed prior to client request handling. The container does not call the init() method again, unless a servlet is reloaded. After the instantiation and initialization are completed, the servlet container calls the service() method to respond to the request. When the servlet is no longer needed, the container destroys the servlet with the destroy() method. This method is also executed only one time.