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Acknowledgments
This book was not possible without support from a multitude of people.
First and foremost, many thanks to OReilly for trusting in me and providing an opportunity to write this book. Their team provided excellent support throughout the editing, reviewing, proofreading, and publishing process.
At OReilly, Michael Loukides helped me with bootstrapping the book. Meghan Blanchette provided excellent editorial help throughout all the stages, helping with interim reviews, providing feedback on styling, arranging technical reviews, and connecting me with the rest of the team when required. Jessica Hosman helped me in getting started and guided the authoring process.
Emily Quill and Kristen Borg helped with copyediting and making sure to provide the finishing touches. And thanks to the rest of the O'Reilly team with whom I did not interact directly, but were helping in many other ways.
The detailed proofreading and technical review by Markus Eisele (@myfear, http://blog.eisele.net), John Yeary (@jyeary, http://javaevangelist.blogspot.com), and Bert Ertman (@BertErtman, http://bertertman.wordpress.com) ensured that the relevant content was covered accurately. Their vast experience and knowledge showed in the depth of their comments.
I am grateful for the numerous discussions with developers around the world that helped me understand the technology better. Thanks to my colleagues at Oracle and the JSR specification leads for explaining the intended use cases of different technologies. And thanks to everybody else in my life, who provided much-needed breaks from book writing.
Chapter 1. Java Platform, Enterprise Edition
Introduction
The Java Platform, Enterprise Edition (Java EE) provides a standards-based platform for developing web and enterprise applications. These applications are typically designed as multitier applications, with a frontend tier consisting of web frameworks, a middle tier providing security and transactions, and a backend tier providing connectivity to a database or a legacy system. The Java EE platform defines APIs for different components in each tier, and also provides some additional services such as naming, injection, and resource management that span across the platform. Each component is defined in a separate specification that also describes the API, javadocs, and expected behavior.
The Java Platform, Enterprise Edition 6 (Java EE 6) was released in December 2009 and provides a simple, easy-to-use, and complete stack for building such applications. The previous version of the platform, Java EE 5, took the first step in providing a simplified developer experience. The Java EE 6 platform further improves upon the developer productivity features and also adds a lot more functionality.