The three large scope objects of the servlet and the nine built-in objects of JSP and their four scope objects __servlet

The three major scope objects of the servlet:

Request (HttpServletRequest)

Session (HttpSession):

Application (ServletContext): Tomcat was created when it was started, destroyed when Tomcat was shut down, and the entire Web lifecycle was only one

The class corresponding to it in parentheses

The nine main built-in objects of JSP:

PageContext (PageContext)

Request (HttpServletRequest)

Session (HttpSession)

Application (ServletContext)

Response (HttpResponse)

Config (servletconfig)

Out (JspWriter)

Page (Object)

Exception (Throwable)

The corresponding classes in parentheses, which are present in the JSP, can be used directly in the

Four scope objects for JSP:

PageContext (PageContext)

Request (HttpServletRequest)

Session (HttpSession)

Application (ServletContext)

The class corresponding to it in parentheses