Document Root of the Application.
Document Root of the Application.
In addition to web components and web resources, a web module can contain other files:
Server-side utility classes (database beans, shopping carts, and so on). Often these classes
conform to the JavaBeans component architecture.
Client-side classes (applets and utility classes).
A web module has a specific structure. The top-level directory of a web module is the document
root of the application. The document root is where JSP pages, client-side classes and archives,
and static web resources, such as images, are stored.
The document root contains a subdirectory named WEB-INF, which contains the following files
and directories:
web.xml
: The web application deployment descriptor
Tag library descriptor files (see
classes
: A directory that contains server-side classes: servlets, utility classes, and JavaBeans
components
tags
: A directory that contains tag files, which are implementations of tag libraries (see
lib
: A directory that contains JAR archives of libraries called by server-side classes
If your web module does not contain any servlets, filter, or listener components then it does not
need a web application deployment descriptor. In other words, if your web module only
contains JSP pages and static files then you are not required to include a web.xml file. The
hello1
example, first discussed in
pages and images and therefore does not include a deployment descriptor.
You can also create application-specific subdirectories (that is, package directories) in either the
document root or the WEB-INF/classes/ directory.
A web module can be deployed as an unpacked file structure or can be packaged in a JAR file
known as a web archive (WAR) file. Because the contents and use of WAR files differ from those
of JAR files, WAR file names use a .war extension. The web module just described is portable;
you can deploy it into any web container that conforms to the Java Servlet Specification.
To deploy a WAR on the Application Server, the file must also contain a runtime deployment
descriptor. The runtime deployment descriptor is an XML file that contains information such
as the context root of the web application and the mapping of the portable names of an
application's resources to the Application Server's resources. The Application Server web
application runtime DD is named sun-web.xml and is located in the WEB-INF directory along
with the web application DD. The structure of a web module that can be deployed on the
Application Server is shown in
Web Modules
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