Enterprise JavaBeans 3rd Edition
As many Java developers and IS managers already know, Sun's powerful Enterprise JavaBean (EJB) technology offers an attractive option for developing server-side components.
A suitable read for both managers and Java programmers, Enterprise JavaBeans provides a surprisingly clear and engaging introduction to designing and programming with EJBs.
The tour of the EJB component model presented here centers on several beans created and tested for a travel reservation system in a fictitious cruise ship company. The samples are just right in scale, large enough to test out key concepts in design and deployment, but small enough to be comprehensible, even to those who are not Java experts. The author pays close attention to the real-world issues of deployment with EJBs (as well as the differences among the vendor application servers that run them). Local interfaces are thoroughly discussed as well. Local interfaces allow beans that are co-located to interact without the overhead of remote method calls. This improves the performance of beans considerably and complements the CMP relationship fields. Message driven beans are a new kind of enterprise bean based on asynchronous messaging and the Java Message service (JMS). Instead of responding to Java RMI calls, message driven beans process JMS messages sent by messaging clients. An entire chapter is devoted to message-driven beans and how to use them effectively. The new version of container-managed persistence (CMP) beans in 2.0 is more portable and robust than in the older 1.1 version. Most significant is the introduction of the relationship fields, which allow entity beans to declare relationships with each other as natural references. In order to make this huge leap in component relationships possible, EJB 2.0 had to redesign how entity beans are defined and interact. Our new 3rd edition examines this critical CMP model in detail.