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Over a decade, web applications have evolved from static HTML pages, to dynamic HTML (DHTML) pages, to pages using applets and Flash, and finally, to those incorporating Ajax (Asynchronous JavaScript and XML) technologies. Two great examples of Ajax are Google Maps and Google Suggest. Ajax breathes new life into web applications by delivering the same level of interactivity and responsiveness as desktop applications. However, unlike applets or Flash, Ajax is based on the standard browser and JavaScript, and no proprietary plug-in is required.

ZK runs as a set of Java servlets inside a Java servlet container. In this chapter, I will guide you through the required installation step by step; it includes installing the Java runtime environment, installing a Java servlet container, and deploying the WAR file (I’m assuming that your operation system is Microsoft Windows 2000+).

Since we set up the environment for running a ZK application in the previous chapter, in this chapter, I am going to guide you through making your first ZK application. We’ll create the simplest, but most famous, program: Hello World. In addition, you will see how easy it is to customize a ZK component with its properties, as well as a demonstration of Ajax in ZK, and I’ll explain its concept of behind-the-scenes technology. Now, follow the instructions in this chapter to complete your first mission!

After reading through the previous chapters, you should have some feeling about how to write ZK web applications. In this chapter, I will discuss the basic concepts of the ZK Ajax Framework in more detail, which will prepare you to create the real application in Part 2 of this book.

This chapter tells you how to prepare your development environment for building a ZK Ajax web application. You should follow these steps to set up an environment for developing ZK applications:

In the previous chapter, you should have prepared your Eclipse IDE for developing a ZK Ajax web application. In this chapter, I will show you how to implement a real ZK web application step by step, so you can see the whole life cycle of developing a web application with ZK.

Now that you’ve finished creating the GUI pages, it is time to handle the database part. The original Java Pet Store 2.0 sample program uses a Java persistent API (EJB3) to persist the model object. In ZK Pet Shop, I will use the Hibernate persistent layer to do the same thing. The good news is that the persistence mechanisms of EJB3 and Hibernate are almost the same, so the only thing you’ll have to do is replace the EJB3 entity manager with Hibernate’s thread session facility to handle database transactions.

In previous chapters, ZK Pet Shop demonstrated the power of ZK by allowing you to separate a web application into its model, view, and controller parts without much effort. Now, we are going to make moving data between ZK components and the data model smoother, especially the plumbing code—loading data from the model to the ZK components and saving data from ZK components to the data model.