A JSP page is converted into servlet before service requests. JSP Lifecycle consists of following phases:
JSP Page Translation:
The container validates the JSP page and parse it to generate the servlet file.
JSP Page Compilation:
The generated servlet file is compiled into a servlet class.
Class Loading:
Container loads the generated servlet class into memory.
Instantiation:
Container invokes the no argument constructor of generated servlet class to load it into memory and instantiate it.
Initialization:
After creating the instance, jspInit() method is called to initialize it.
Request Processing:
The _jspService() is called by web container every time when a request is come for the jsp.
Syntax:
public void _jspService() throws ServletException,IOException
Note: In this method underscore (_) represents that implementation of this method is provided by auto generated servlet and it can’t be overridden by developer.
Destroy:
The jspDestroy() method is called by web container to unload JSP from memory.