What is it all about?
With the J2EE Courses we want to give you during 4 IEEE Specials an introduction into software developement with the Java 2 Enterprise Edition. We will try to demonstrat with small examples the possibilities of the J2EE. We use the open source application server JBoss and will publish all examples here, too.
What is the J2EE?
The Java 2 Enterprise Edition is a Standard for so called multitier applications in Java. Multitier means applications distributed over multiple architectural layers. The J2EE provides a component architecture which the developer can use for implementing the business logic. The goal of the J2EE is to keep all problems not directly related to the business logic away from the developer.
Therfore the J2EE defines a standard for so called applications servers (for example BEA Weblogic, IBM Websphere, JBoss and others). The application server provides various services for the components, which the developer would have to implement himself otherwise. This goes from transaction management, messaging, remoting, etc. as far as integrating not J2EE based components. So the J2EE externalizes a lot of "framework problems" to the application server, and allows the developer to fully concentrate on designing the business logic.
Why you should come
The Java 2 Enterprise Edition can no longer be ignored when developing business-critical applications. A growing Part of big business applications is currently developed based on the J2EE. In the future it can be excepted that the importance of the J2EE will further grow. When developing buisness software, the J2EE has at least to be considered as a viable solution because she often poses a huge advantage over custom or vendor-specific frameworks. As developer of business software one will probably not be able to avoid J2EE developement. And besides, one can simply do cool things with it :)
Literature and Web-Sources
Part 1 - Overview and Basics
In the first of four events we give you a big overview of the parts of the J2EE and explain which problams during application developement can be solved using the J2EE. We talk about JNDI as connection between the parts of the J2EE. In addition we give you a short introduction into the application server JBoss, its installation and usage.
Part 2 - EJBs - Remoting, Transactions, Security with JAAS
This time we travel into the depths of EJBs. First we present the basic elements of an EJB and show you the deployment in the application server. We continue with remoting, we access our EJBs from a client application. Then we show you the possibility for declarative transaction on method level and rejoice because we don't have to do manual commit and rollback anymore. And finally we secure our EJBs using JAAS.
Part 3 - EJBs - Persistence and EJB Design Patterns
In the third part we examine the possibilitys to do object persistence with EJBs. Using Entity Beans we get database agnostic, and create an object-orientated persistence model. We will of course also show the problems of EJBs and learn some design patterns to avoid those. Eventually we will cover alternatives to Entity Bean persistence like OR-Mapping Frameworks (for example Hibernate) or JDO.
Part 4 - Messaging with JMS, Code Generation with XDoclet
In the final part of the series we cover robust messaging with the Java Message Service (JMS). With JMS we send reliable messages between the distributed components of our application and create an asynchronous messaging system. Finaly we take a look at how the developement for the J2EE can be greatly simplified using XDoclet for automatic code generation.