What built-in objects does JSP have? What are their roles? What are the methods? -Pen questions from many companies (learn to answer questions without having to do it)

JSP has nine built-in objects:
request a user-side request, this request will contain parameters from the get/POST request
response returned from the response webpage to the user end
the attributes of the pagecontext webpage are managed here
session related to the request
content being executed by application servlet
output for sending response
framework component of config servlet
page JSP page itself
exception for errors webpage, uncaptured exceptions

request indicates the httpservletrequest object. It contains information about browser requests and provides several useful methods for obtaining cookie, header, and session data.
response indicates the httpservletresponse object, and provides several methods (such as cookies and header information) for setting the response sent back to the browser.
The out object is javax. JSP. an example of jspwriter, and provides several methods for you to send the output results back to the browser.
pagecontext indicates a javax. servlet. jsp. pagecontext object. It is used to facilitate access to various namespaces and servlet-Related Object APIs, and encapsulates common servlet-related functions.
session indicates the requested javax. servlet. http. httpsession object. Session can store user status information
applicaton indicates a javax. servle. servletcontext object. This helps you find information about the servlet engine and Servlet environment.
config indicates a javax. servlet. servletconfig object. This object is used to access the initialization parameters of the servlet instance.
page indicates a servlet instance generated from this page