building a web application in eclipse

Question

As a concluding assignment for the technologies taught in a data management course, we have to write a web application using the technologies taught throughout the course, this mostly includes xhtml, css, JSP, servelets, JDBC, AJAX, webservices. the project will eventually be deployed using tomcat. we are given the option of choosing the technologies that we see fit. since this is my first time developing a web application I am having some uncertainties about where to start, so for example now I am writing the object classes that will be used in the database and implementing the operations that will be performed on the database, but I am not sure about how to make these operations available to a client through the website, I mean I think I have to write a servlet through which I can extract the request parameters and set the response accordingly, but I would still like a more specific overview of what I am going to do, so if someone can link me to a tutorial with an example that makes use of these technologies while illustrating the stages of the design so that I can see how all these things are linked together in a web project.

thanks

Answer 1

Java Enterprise applications typically use a layered architecture as illustrated below:

In short:

• The presentation layer provides the application's user interface. In a web application, this typically involves the use of a MVC (Model-View-Controller) framework.
• The service layer exposes coarse grained services implementing the business logic of an application. They act as entry point and are typically responsible of transaction demarcation.
• The data access layer abstract physical storage systems (e.g. a database) and expose CRUD (Create, Read, Update, Delete) methods and finders.
• Domain objects represent the business concepts of your domain (Client, Order, Product, etc) and are typically used across all layers, from the data access layer to the presentation).

I don't want to make things too confusing and to throw in too much technologies or frameworks (are you allowed to use frameworks?) that could fit in this diagram. Just tell me if I should.

Regarding your question about the presentation layer, I already hinted the answer: use the MVC pattern.

Basically, the View is the part that renders the user interface (e.g. JSP). From the view, the user sends input to a controller (a Servlet acting as entry point). The controller communicates and interacts with the model (standard Java classes), set appropriate data in the HTTP request or Session and forwards the request and response to a view. And this restarts the cycle.

If you need more details, let me know.

Answer 2

Baby steps are needed. Get something running and then expand on it.

Start with this tutorial, get it running and then start asking questions http://www.eclipse.org/webtools/community/tutorials/BuildJ2EEWebApp/BuildJ2EEWebApp.html

This will give you a Servlet and a JSP running on Tomcat from Eclipse. From there you can expand.

Answer 3

Sun documentation is pretty good: The Java EE 6 Tutorial, Volume I.

There is also a working sample application released by the Java BluePrints program at Sun called the Pet Store Demo.

I have also put together a string of tutorials aimed at beginners who are wanting to learn how to build Java web applications (within the Eclipse environment). I have tried to keep it as simple as possible.