The HttpPage interface defines the methods that an HTTP Java Server Page must implement. Almost all current implementations of JSP only support HTTP. In the future, as wireless protocols such as WAP become more prevalent, you might see other interfaces such as WAPPage.
_jspService public void _jspService(HttpServletRequest request HttpServletResponse response) throws ServletException, java.io.IOException
This is the main service method for the JSP. It contains any scriptlets and expressions embedded in the page as well as any support code needed to display the JSP. This method is automatically generated by the JSP compiler. You should never implement this method yourself.