What is an enterprise application?
Enterprise applications are the strategic applications in the enterprise. They will handle critical business functions and tend to be big and complex. In the past, it was acceptable that users had to take training classes before they were able to use the application, but today, enterprise applications are also required to be user friendly and intuitive. As they are deployed throughout the organization, they will need sophisticated security features. Enterprise applications will remain in use for a long time because of the cost of developing and implementing them.
Application size
An enterprise application is big—containing lots and lots of code modules, interacting in complex ways among themselves and with external systems.
Typically, this means that an enterprise application also has a lot of different screens where the user will interact with the system. However, it is also possible that the complexity of the enterprise application is hidden from the user; a good enterprise application might seem deceptively simple to the average user.
Development team
The complexity of an enterprise application means that it will have to be built by a larger team. It will use several technologies, so you need people skilled in all of the relevant areas. You will need to have people working in parallel on different parts of the application in order to develop it within a useful timeframe because of its sheer size.
An enterprise application cannot simply be partitioned out among developers because of the interdependencies among the different parts of the application. Instead, development work must be carefully planned so that the foundation is laid down before the rest of the house is built while, at the same time, allowing for the inevitable changes as the project progresses.
Development tools
Naturally, you need an Integrated Development Environment (IDE) to build the actual application. This book assumes that the entire team will be using Oracle's free JDeveloper tool for all work. The choice of IDE can be the subject of almost religious fervor, and some projects allow each developer to choose his or her favorite IDE. However, in an enterprise project, the benefits of having everyone use the same tool clearly outweighs any minor benefit achieved by using other IDEs with marginally better support for one or the other task.
In addition to the IDE, you will also need source control—a server holding all of the different versions of the development artifacts and a client on each development workstation. This book uses both Subversion and Git as examples of how to use source control in an enterprise project with JDeveloper.
Another important tool is an issue-tracking tool. This can be used to track defects in code as well as ideas, development tasks, and many other things. In this book, the well-known Jira tool is used, and it is explained how this tool fits the Oracle Team Productivity Center (TPC).
Finally, you need a scripting tool. In a small project, it might be sufficient to build applications directly off of the IDE, but in an enterprise application, you need a tool to ensure that you can build your project in a consistent manner. This book uses Ant as an example of a scripting tool for the ADF projects.
Lifetime of an enterprise application
Enterprise applications are not casually thrown away and rebuilt because of the effort and cost involved in building them. Indeed, many organizations are still running enterprise applications built more than a decade ago.
The longevity of enterprise applications makes it extremely important that they are well built and well documented. Most developers will be familiar with the pain of having to maintain a poorly documented application and understand the need for a good documentation.
However, while documentation is important, it is just as important that the application is built in a recognizable, standard way. That is why this book advocates using the ADF framework in its intended way so that the future generations of developers can look at the code and immediately understand how the application is built.