This book has been written mainly from the perspective of Java/J2EE job seekers and interviewers. There are many books and articles on the market covering specific topics such as Java, J2EE, EJB, Design Patterns, ANT, CVS, Multi-Threading, Servlets, JSP, emerging technologies like AOP (Aspect Oriented Programming), Test Driven Development (TDD), Dependency Injection Dl (aka the IOC - Inversion Control) etc. But from the perspective of the interview was not possible to brush at all these books where each book usually has from 300 pages 600 pages. The basic purpose of this book is to cover all the core concepts and key areas, which all Java/J2EE developers, designers and architects should be conversant with a good performance in their current jobs and to launch a successful career by doing well in interviews. I also at one stage had not decided whether to name this book "Java/J2EE core concepts and key areas" or "Java/J2EE Job Interview Companion". The reason I chose "Java/J2EE Job Interview Companion" is because the core concepts and key areas discussed in this book helped me to become successful in my interviews, helped me to survive and succeed in the workplace I do not care what my job (junior developer , senior developer, technical lead, designer, contractor, etc.), and also gave me the thumbs up in code reviews.