16.2 Packaging the Application as a WAR File


Packaging your web applications using the WAR format is very convenient. The structure is precise, and because it is specified so carefully, porting your applications across the various web containers is much easier. The next section describes the steps that you must perform to package your web application as a WAR file.

16.2.1 Creating the WAR File

The first step in packaging your application as a WAR file is to create a root directory. In most cases, this directory will have the same name as your web application. For our example, we will create a directory called storefront.

After deciding how your JSP and HTML pages will be placed within your application, place them underneath the root directory in their appropriate subdirectories. For the Storefront example, our directory structure so far would look like Figure 16-2.

Figure 16-2. The Storefront application directory structure
figs/jstr2_1602.gif


Figure 16-2 shows 11 subdirectories, 8 of which contain JSP pages for the application. The images directory contains images that are used globally throughout the application, the stylesheets directory stores cascading stylesheets for the application, and the include directory contains files that are included using either a static or dynamic include.

The next step in setting up the WAR file is to ensure that you have a WEB-INF directory underneath your root web application directory. The WEB-INF directory contains all of the resources that are used internally by the application. For example, the TLD files for your custom tag libraries reside in this directory, as does the web deployment descriptor. This is also where the Struts configuration files belong. No resource within this directory can be made public outside of the application.

Underneath the WEB-INF directory, create two subdirectories: one called classes and the other called lib. The classes directory should contain all of your utility and servlet classes. The lib directory should contain the JAR files that the application depends on.

Once all of the resources for the web application are accounted for and are inside the appropriate directories, you need to use Java's archiving tool jar to package the directories and files. From a command line, change to the root directory of your web application and use the jar utility. You need to give the file a .war extension, like this:

jar cvf storefront.war .

Because you changed to the root directory, the storefront directory will not be included in the WAR file. This is fine, because you may want to call the root directory something else when it's installed. When you install the web application, if you plan to explode the WAR file, all you need to do is create a directory and un-jar the files, like this:

C:\tomcat\webapps>mkdir storefront C:\tomcat\webapps>cp storefront.war storefront C:\tomcat\webapps>cd storefront C:\tomcat\webapps\storefront>jar xf storefront.war

The location where the WAR file gets expanded is container-dependent. If you plan to distribute the WAR file without exploding it, all you have to do is place it in the appropriate place for the container. You don't have to recreate the storefront directory, although you might want to delete the existing directory when deploying a newer version.

Although Section 9.8 of the 2.3 Servlet specification is a little ambiguous about replacing a web application without restarting the server, most containers allow you to drop in a new WAR file or replace certain files without restarting. There's always a danger with leaving this feature on in a production environment; however, while developing the application or debugging a problem, you'll quickly learn to appreciate this functionality. In containers that do support this feature, there's usually a way to disable it when you deploy a web application into production.




Programming Jakarta Struts
Programming Jakarta Struts, 2nd Edition
ISBN: 0596006519
EAN: 2147483647
Year: 2003
Pages: 180

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