Chapter 12: Web Applications

Overview

The World Wide Web is the largest distributed application in the world. Currently, however, nonstandardized and inflexible HTML interfaces are the main technique used to access the wealth of components—Web sites—out there. Although these interfaces are relatively easy to use for humans, they are not suitable for building complex applications. One of the current efforts to improve this situation are so-called Web services. Web services are aimed at establishing a uniform infrastructure for the description and registration of Web-based services and for providing access to these components.

However, the big challenge in the development of a Web application is still the building and integration of local components, where local means "belonging to a single Web provider." There are currently many frameworks and libraries devised to make it easier for Java programmers to develop Web applications. For example, the large Apache ^[1] project Jakarta [URL:Jakarta] includes many small projects, considering the wide range of aspects involved in Web programming. The technical basis for all kinds of different efforts are still primarily servlets and Java Server Pages (JSPs). Hunter and Crawford [01] and Pekowsky [00] provide two examples of textbooks introducing these technologies.

The fact that, similarly to EJBs, servlets require the context of a server makes testing on unit level a costly venture. Fortunately, the servlet API is much more transparent and easier to isolate. This chapter attempts to discuss testing in reverse order: we will first describe functional testing, then discuss interaction tests, and finally try a fine-grained test-first approach.

^[1]The Apache Software Foundation hosts and drives a lot of open source projects. It's best known for the Apache Web Server.