TABLE OF CONTENTS Previous chapters of this book have focused on features included in the Java WS Core and Authentication & Authorization components of GT4. The chapters used a simple example, MathService, to illustrate fundamentals of service development in GT4. Although MathService is a good way of making first contact with GT4, its simplicity does not allow for interesting higher-level discussions.
And so the final chapters of this book are built around a new example application called FileBuy. The FileBuy system is composed of multiple services deployed across several machines. The additional complexity in FileBuy enables us to highlight a few design patterns commonly found in GT4-based systems. It should be noted that in order to maintain focus on GT4, many details of a real-world system have been intentionally simplified in our example.
The FileBuy section is composed of two chapters, the first of which focuses on design considerations. The second chapter includes a discussion of implementation details and instructions on how to deploy the application. The source code for FileBuy can be downloaded from the book's website (http://www.gt4book.com/).
In this chapter we present an overview of the design of FileBuy. FileBuy is a resource brokering system, and so we begin with a conceptual overview of resource brokering. Then, using a simplified form of UML, we walk through three usage scenarios of the system. The chapter concludes with a brief discussion on security considerations and a review of the important design concepts seen...
