2.5.1

Web Applications

A Web Application is a collection of resources that are available through some URLs. The 

resources include JSP pages, Java Servlet classes, static pages and other Java technology 

based resources and classes to be used at the server side as well as Java resources and classes 

(like Applets, JavaBeans components, and others) which are to be downloaded for use by the 

client. A Web Application is described in more detail in Chapter 9 of the Servlet 2.2 

specification.

A Web Application contains a deployment descriptor 

web.xm

l that contains information 

about the JSP pages, Servlets, and other resources used in the Web Application. The 

Deployment Descriptor is described in detail in Chapter 13 of the Servlet 2.2 specification.

JSP 1.1 requires that all these resources are to be implicitly associated with and accessible 

through a unique 

ServletContext

 instance, which is available as the 

application

implicit object (Section 2.8). The JSP specification inherits the notions of a Web Application 

from the Servlet 2.2 specification.

The application to which a JSP page belongs is reflected in the 

application

 object and 

has impact on the semantics of the following elements:

The 

include

 directive (Section 2.7.6)

The 

jsp:include

 action element (Section 2.13.4).

The 

jsp:forward

 action (Section 2.13.5).

2.5.2

Relative URL Specifications within an Application

Elements may use 

relative URL specifications

, which are called  URI paths  in the Servlet 

2.1 specification. These paths are as in RFC 2396 specification; i.e. only the path part, no 

scheme nor authority. Some examples are:

 myErrorPage.jsp 

 /errorPages/SyntacticError.jsp 

 /templates/CopyrightTemplate.html 

When such a path starts with a  / , it is to be interpreted by the application to which the JSP 

page belongs; i.e. its 

ServletContext

 object provides the base context URL. We call 

these paths  context relative paths .

When such a path does not start with a  / , it is to be interpreted relative to the current JSP 

page: the current page is denoted by some path starting with  /  which is then modified by 

the new specification to produce a new path that starts with  / ; this final path is the one 

interpreted through the 

ServletContext

 object. We call these paths  page relative 

paths .

Chapter 2

Standard Syntax and Semantics

40