Catálogo de publicaciones - libros

The preceding definition of is usually used when discussing sewing. However, this definition also fits the latest in frameworks from JBoss—JBoss Seam. is a framework that brings together existing Java Platform, Enterprise Edition (Java EE) standards to enable them to work as an integrated solution. At its core, the Seam framework ties the Enterprise JavaBeans 3 (EJB3) and JavaServer Faces (JSF) specifications. However, Seam does not just stop there—it will also join together other component models that you may be used to, such as jBPM, Drools, and more that we will get into as the book progresses.

Chapter 1 outlined the concepts of MVC and gave a brief discussion of web frameworks. The main reason for that discussion was to help you understand any major web framework that has come out since 2000. In this chapter, however, I want to go over two things: a more detailed review of the web server side, and an introduction to the web applications used in this book.

As mentioned in Chapter 1, there are two component pieces that Seam uses to provide seamless integration between frameworks. The first component that I am going to discuss is the presentation tier component. Currently the only presentation component that is supported by Seam is JavaServer Faces (JSF), so a good background and basic knowledge of it is a must. As you can see from the road map diagram in Figure 3-1, we will focus on only the presentation tier in this chapter.

This begins the second and final of our “fundamental” chapters, and if you are not familiar with Enterprise JavaBeans (EJBs) at all, then definitely take a close look at this chapter. Because Seam applications rely almost exclusively on EJBs to provide the domain and business logic, this chapter is important in understanding how to implement a Seambased application. This chapter focuses almost exclusively on the Entity JavaBeans 3 specification (EJB3) but will touch on how to call EJBs from the client. The road map in Figure 4-1 shows where the focus of this chapter lies.

The preceding two chapters covered the EJB3 and JSF frameworks, which are the core components of Seam. In those chapters, you learned a simplistic way of designing both presentation and business logic. However, in order to have the JSF pages call the business logic, we had to go through JSF backing beans, the intermediate classes. Doing so often required adding code referencing the backing beans in faces-config.xml.

As you may recall, in Chapter 5 I talked about contexts. There are seven of them, and I gave a brief description of what they are and how they are used. To review, the contexts are as follows:

Business process management tools are used by businesses to increase their speed and efficiency in the workplace. The basic purpose of business process tools is to create a way to document business processes outside of the code. A business process itself generally references a sequence of steps that are followed to complete a process—anything from creating a trouble ticket at work to ordering from an online merchant. The processes generally have alternate paths to follow and generally involve some level of multiple-user interaction. The business process tool we use for Seam is .

Although I have called this chapter , do not be scared. This does not mean that this chapter is exponentially harder—in fact, I would argue that the preceding two chapters were probably the hardest to understand conceptually, because they presented ideas that most people do not work with on a daily basis. This chapter covers topics that are nice goodies to have in any web application: internationalization, Ajax, and security. It also covers web services, with a focus on RESTful web services. In addition, it covers Drools support and a new idea called themes. Ideas outlined here should help you make the most of Seam and to expand your web applications to be as dynamic as possible.

We are now going to turn our efforts to looking at the different ways to configure Seam. Obviously, we have already gone over configuring and deploying Seam and by now have deployed quite a few applications. However, Seam has the ability to be leveraged in multiple environments under multiple conditions. To use Seam, you do not actually have to be in a Java EE environment or even be using EJB3 if you do not want to (it is preferred, though). Of course, you will have to use Java 5; there is no way around that.

This brings us to our final chapter in learning Seam. Although this chapter is the last, it is certainly not the least. This chapter covers two concepts: testing and tools.