Secondary abstract: |
In five decades of its existence, internet has journeyed the path from the shy beginnings within USA's ministry of defense, to contemporary web applications, which can in many ways hold its ground against their desktop competitors. The main reason for the blossoming of web applications in recent years can be attributed to the use of AJAX, which enables high responsiveness and interactive experience, thanks to the use of asynchronous communication between the server and the client. The thesis uses application PresalesTracker as an example to show how AJAX behaves and which are the necessary parts of a modern web application.
The development of AJAX applications without the help of frameworks would be tedious and time consuming, thus making AJAX frameworks a component of paramount importance for the development of modern web applications. One such framework is ZK, which enables a simple creation of user interface, through the use of a markup language called ZUML. By determining which browser it is running in, which version of JavaScript is in use, how to display HTML components etc., ZK framework enables the developer to develop a unified web application for all browsers, without the extra work, needed to get the JavaScript code running in all browsers. All processing occurs on the server, reducing the hardware requirements of the client to a minimum.
Whereas the user interface is the most visible part of a web application, the business logic is more important for the proper operation. Just like with user interface development, several frameworks are available to simplify the development of business layer. PresalesTracker application uses Java EE framework, which provides means for a simple implementation of business logic, through the use of EJB beans. Furthermore, JPA framework simplifies access to the database and provides mapping of database objects to Java objects. |