The following implicit objects are always available within scriptlets and expressions:
Request – the request triggering the service invocation.
Response – the response to the request.
PageContext – the page context for this JSP.
Session – the session object created for the requesting client (if any).
Application – the servlet context obtained from the servlet configuration, as in the call getservletConfig().getContext().
Out – an object that writes to the output stream.
Config – the ServletConfig for this JSP.
Page – the instance of this page’s implementation class that is processing the current request. A synonym for this when the programming language is Java.
For information about the scope and type of each implicit object, see the JavaServer Pages Syntax Card http://java.sun.com/products/jsp/syntax.pdf.
If the JSP is an error page (the page directive’s isErrorPage attribute is set to true), the following implicit object is also available:
exception – the uncaught Throwable that resulted in the error page being invoked.
For more information, see “Error handling”.