Tomcat Server

Tomcat is not too hard to get up and running. I suggest looking at Marty Hall's tutorial for setup..

When it is running, it looks like this. The application also provides you with examples for Servlets and JSPs .
(But note that these say that the code is not complete in these examples).

Below are two examples of the directory structure used in Tomcat. The first is from the Murach book on Servlets and JSPs using Tomcat, and the second is from the Tomcat notes given with Tomcat. Finally, at the end of the page is a gif from the J2EE tutorial in the Java Web Server.

For submission of the labs, you should either have your code working on the ecst server OR provide me with a .war file that can easily be placed in the webapps directory on my machine and provide me with a webpage to call it (i.e., tell me exactly what to do to start it - if I need to do things for a database, etc be very explicit. If explicit directions are not given, I assume you have an index.html in the .war file and that I should be able to start it with simply the name of your .war file from my server).

A web module must be packaged into a WAR in certain deployment scenarios and whenever you want to distribute the web module. You package a web module into a WAR using the Application Server deploytool utility, by executing the jar command in a directory laid out in the format of a web module, or by using the asant utility.

Here is a snapshot of the directory structure for an example application of a Music Store(courtesy of the Murach book)

Description

A Java web application is a hierarchy of directories and files in a standard layout defined by the J2EE specification. This means that each Tomcat web application must use the four directories summarized above.

To organize your Java class files, you can store them in packages. A package of classes must be stored within a subdirectory of the WEB-INF\classes directory.

If you need to make classes within a JAR file available to more than one web application, you can put the JAR file in Tomcat's webapps\common\lib directory. If you need to make classes within a JAR file available to a single web application, you can put them in the WEB-INF\lib directory for that application.

You can use the WEB-INF\etc directory to store any files that you don't want users to be able to access. For example, you can store any files that store data for the application in this directory.

Standard Directory Layout - from Tomcat notes
To facilitate creation of a Web Application Archive file in the required format, it is convenient to arrange the "executable" files of your web application (that is, the files that Tomcat actually uses when executing your app) in the same organization as required by the WAR format itself. To do this, you will end up with the following contents in your application's "document root" directory:
- *.html, *.jsp, etc. - The HTML and JSP pages, along with other files that must be visible to the client browser (such as JavaScript, stylesheet files, and images) for your application. In larger applications you may choose to divide these files into a subdirectory hierarchy, but for smaller apps, it is generally much simpler to maintain only a single directory for these files.
- /WEB-INF/web.xml - The Web Application Deployment Descriptor for your application. This is an XML file describing the servlets and other components that make up your application, along with any initialization parameters and container-managed security constraints that you want the server to enforce for you. This file is discussed in more detail in the following subsection.
- /WEB-INF/classes/ - This directory contains any Java class files (and associated resources) required for your application, including both servlet and non-servlet classes, that are not combined into JAR files. If your classes are organized into Java packages, you must reflect this in the directory hierarchy under /WEB-INF/classes/. For example, a Java class named com.mycompany.mypackage.MyServlet would need to be stored in a file named /WEB-INF/classes/com/mycompany/mypackage/MyServlet.class.
- /WEB-INF/lib/ - This directory contains JAR files that contain Java class files (and associated resources) required for your application, such as third party class libraries or JDBC drivers.
When you install an application into Tomcat (or any other 2.2/2.3-compatible server), the classes in the WEB-INF/classes/ directory, as well as all classes in JAR files found in the WEB-INF/lib/ directory, are made visible to other classes within your particular web application. Thus, if you include all of the required library classes in one of these places (be sure to check licenses for redistribution rights for any third party libraries you utilize), you will simplify the installation of your web application -- no adjustment to the system class path (or installation of global library files in your server) will be necessary.

Finally, here is the gif from the J2EE sun tutorial

Note also:
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 J2EE 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 /WEB-INF/ along with the web application DD. The structure of a web module that can be deployed on the Application Server is shown in the above figure.

Tomcat Server

Description

Standard Directory Layout - from Tomcat notes