JSP nine kinds of objects detailed tutorial

Nine kinds of objects of JSP I am Brief:
Page
Application
Request
Response
Session
Config
Out
PageContext

Page
<% @page contenttype= "text/html; charset=gb2312 "language=" java import= "java.sql.*"%>

Response
<%
Response.setheader ("Pragma", "No-cache");
Response.setheader ("Cache-control", "No-cache");
Response.setdateheader ("Expires", 0);
%>

<%response.sendredirect ("login.jsp");%>

Session
<%session.invalidate ();%>

Request/session
<%
String errmsg = Request.getparameter ("errmsg");
Request.getsession (TRUE);
String chk = "false";
Session.putvalue ("Enter", chk);
%>

Out
<%
if (errmsg!= null && errmsg.equals ("Error1"))
Out.print ("Your user number has not yet opened!!");
else if (errmsg!= null && errmsg.equals ("Error2"))
Out.print ("You enter Administrator account number or incorrect password!!");
%>

The following is a description of the request object in Java Doc: other similar