SAIP: J2EE and EJB

Chapters 16 and 17 are case studies on systems that utilize Java and its technologies.

Chapter 16 was a description of the architecture of J2EE and how it achieved the quality attributes of its stakeholders for distributed computing. However, it was too detailed for me to appreciate since I have not used J2EE or EJB before. It did point out the robustness of J2EE and how Sun Microsystems invested a lot of time and money to make it handle most of the situations. One interesting aspect of this architecture was the design to support the older standard for distributed computing using CORBA. I found this to be a wise step on the part of Sun Microsystems; no one is likely to switch over everything to just use your company's new technology. It has to be a gradual shift that helps build confidence in the new product. It was because of neglecting this fact that the Air Traffic Control system we saw back in Chapter 6 did not take off.

Chapter 17 focused on using J2EE for wearable computing devices. These computing devices had unique requirements that had to be catered to. For instance, some of them had small screens, limited input abilities, low power consumption and limited processing power. Sometimes, these devices were so varied that entirely new input/output devices had to be designed from the ground up. While the company, Inmedius Corporation, decided to use J2EE, I am rather surprised that they did not turn to J2ME, the Java standard for mobile devices. J2ME seemed like a better choice for micro devices that had limited processing power since it offers a simpler API and smaller memory footprint.