The generated servlet class for a JSP page implements the HttpJspPage interface of the javax.servlet.jsp package. Hte HttpJspPage interface extends the JspPage interface which inturn extends the Servlet interface of the javax.servlet package. the generated servlet class thus implements all the methods of the these three interfaces. The JspPage interface declares only two mehtods - jspInit() and jspDestroy() that must be implemented by all JSP pages regardless of the client-server protocol. However the JSP specification has provided the HttpJspPage interfaec specifically for the JSp pages serving HTTP requests. This interface declares one method _jspService().
The jspInit()- The container calls the jspInit() to initialize te servlet instance.It is called before any other method, and is called only once for a servlet instance.
The _jspservice()- The container calls the _jspservice() for each request, passing it the request and the response objects.
The jspDestroy()- The container calls this when it decides take the instance out of service. It is the last method called n the servlet instance.

Well @ rominekarte!A JSP page services requests as a servlet. Thus, the life cycle and many of the capabilities of JSP pages (in particular the dynamic aspects) are determined by Java Servlet technology.
JSP page translation
JSP page compilation
load class
create instance
call the jspInit method
call the _jspService method
call the jspDestroy method
When a request is mapped to a JSP page, the web container first checks whether the JSP page’s servlet is older than the JSP page.

Thanks for providing such a wonderful and valuable information for life- cycle methods in JSP, as I was also pursuing knowledge of java and its life cycle but not about JSP page

jsp life cycle has three important methods such as

- init() ->this initalizes the jsp information with the configuration
parameters.

- service : We have to Put business logic here. that is all the request and
responses goes here.

- destroy() : once the process is completed it will be killed.