It stores referece to the implicit objects-
The following example shows how PageContext is used to populate other implicit objects.
public void _jspService (HttpServletRequest request, HttpServletResponse response) throws java.io.IOException, ServletException { ... try { ... application = pageContext.getServletContext (); config = pageContext.getServletConfig (); session = pageContext.getSession (); out = pageContext.getOut (); ... } catch (Throwable t) { ... } finally { ... } }
Provides convenience methods to get and set attributes in different scopes-
This example uses attributes to save and retrieve data in each of the four scopes:
<% // Save data pageContext.setAttribute("attr1", "value0"); // PAGE_SCOPE is the default pageContext.setAttribute("attr2", "value1", PageContext.PAGE_SCOPE); pageContext.setAttribute("attr3", "value2", PageContext.REQUEST_SCOPE); pageContext.setAttribute("attr4", "value3", PageContext.SESSION_SCOPE); pageContext.setAttribute("attr5", "value4", PageContext.APPLICATION_SCOPE); %> <%-- Show the values --%> <%= pageContext.getAttribute("attr1") %> <%= pageContext.getAttribute("attr2", PageContext.PAGE_SCOPE) %> <%= pageContext.getAttribute("attr3", PageContext.REQUEST_SCOPE) %> <%= pageContext.getAttribute("attr4", PageContext.SESSION_SCOPE) %> <%= pageContext.getAttribute("attr5", PageContext.APPLICATION_SCOPE) %>
JSP pageContext Object Example:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>JSP pageContext Object Example</title> </head> <body> <% JspWriter pw = pageContext.getOut(); pw.print("Hello Dinesh....This is another example of JSP 'pageContext' object"); %> </body> </html>
As you can see above, using JSP pageContext object, JspWriter instance is created. Using this JspWriter object, String response is set that displayed on the browser when JSP served a request.