Sun Certified Enterprise Architect for J2ee Technology Study Guide
Authors: Mark Cade, Simon Roberts
Venue:  (2002)

From the Book:Why We Wrote This BookSun certification exams are not tests given after class. If they were, it's unlikely that they would receive the wide ranging industry recognition that they enjoy. These exams are hard, and being hard means that they prove something, and that makes them worth passing. Not everybody does pass, even after repeated attempts. The Sun exams are probably unique in that you don't have to take Sun training to pass, although of course, Sun training is helpful and a good idea to do anyway. The Sun exams have wide-ranging objectives that don't relate to one particular training course. The objectives for the Sun Certified Enterprise Architect (SCEA) for the Java 2 Platform, Enterprise Edition Technology exam are broad; they attempt to capture the main ideas that would be learned over a number of years as a computing professional, typically in a career that spans a longer time frame and more languages than just Java technology.To address these issues, Sun's certification division plans to provide a study guide for each of its tests. This is one of those guides. This book is probably not the only study guide available for the exam, and it's certainly not the only way to prepare for the exam; however, we hope you'll find it helpful and that you'll learn something of value for your professional development, not just how to answer the exam questions. After all, the exam is meant to give you the opportunity to be a better architect, which in the long term will be far more helpful to your career than a piece of paper saying you passed an exam. About the AuthorsBetween us, we have over ten years experience working with Java technology,in terms of developing systems, teaching, and working on the certification exams. We have considerably more experience in the pre-Java technology world of computing, including C, C++, machine languages, hardware design, networking with Transmission Control Protocol/Internet Protocol (TCP/IP), netbios and Novell, and database technologies. We were privileged to be members of the team that developed the architect certification exam, so we have an intimate knowledge of the difficulty of writing questions for this huge topic, and a fairly accurate view of the nature and scope of the exam. We don't claim to know it all, we don't think anyone does, this topic is too large. However, we hope that we have enough background knowledge, enough experience, and the right communication skills, to help you pass the architect certification exam, and to help you realize your potential as an architect.We believe that whatever study method you use, and whatever resources you use to help you, the knowledge you gain will help you build better systems, and thereby become more successful in your work. We became involved in the exam project because we enjoy the thrill of creating a really elegant and successful system, and we wanted to help others experience that same satisfaction. For the same reason, we decided to take on the project that resulted in the book you're now reading. About This BookThe SCEA exam is intended for seasoned computing personnel, and it is not possible to condense all the required knowledge into a single book. This book is a study guide. We've tried to cover the key facts tested in the exam, but you must understand the concepts as well as the facts to pass this exam. You should probably do additional reading, and you must develop a general understanding of the ideas tested in the exam.Some of the exam questions might look at a particular issue from a slightly different perspective than the one presented in this book. That is why it is important that you understand the issues. We deliberately avoided giving you the answers to any questions, which would only devalue the exam. Furthermore, the exam is the subject of ongoing development, with new questions being added and old ones being removed. It's probably obvious that this is done to reduce the chance of cheating, which again would devalue the exam and thereby devalue the effort you put into passing it.Given that this book doesn't just list the answers, what does it do? It introduces the key concepts covered in the exam and clarifies the terminology. This will ensure that you're "on the same page" as the exam developers. It also lists references in which you can find additional discussion of topics that you might want to research. And, it provides self-evaluation questions that are designed to help you determine if you understand the topic.You might be surprised to know that you could disagree with some of the answers given in this book and not be wrong. Architecture depends on the interaction of a great many conflicting forces, and two experienced architects will often come to quite contradictory conclusions about how best to solve a particular problem. Most of the questions in this book carefully enumerate the values of the customer, and, using these values as hints, you should be able to see why a particular answer is listed as correct. However, it's probably more important that you can see the relationship between the correct answers and the alternative answers.In the multiple choice element of the exam there is only one acceptable answer (or combination of answers). Because of this, you must have the ability to evaluate the questions dispassionately. You must answer them based solely on the information provided, and you should avoid the tendency to fill in additional "ifs, buts, and wherefores." Often the real exam lists a possible answer that is perfectly reasonable if you include just one additional value judgement, but because that value judgement is unsupported by the question, the answer is wrong in the context of the exam.Learning to think like this isn't just a skill for getting through the exam, it will help you in your profession because it allows you to evaluate your own decision-making process, and determine if you are applying your own secret values to a decision, or if you are actually responding to a stated customer requirement. If you are an experienced architect, you know that it's OK, even essential in many cases, to use your values to fill in the blanks left by the customer. However, when you do so, you owe it to your customer to communicate your ideas. You might just prompt them to remember additional information.Who Should Read This BookThis book is not intended to give a novice programmer the skills and knowledge needed to pass the exam. It is intended to help complete the knowledge of someone who has several years of computing experience, although not all of that must be using Java technology; in fact you're probably better equipped if you have used other technologies as well. You should be aware of the broad meaning of the technologies discussed, but you do not necessarily have to have experience using all of them.As we wrote the book, we used the following profile as a guide for the type of reader that might find this book helpful. You understand object-oriented concepts, such as encapsulation, inheritance, and polymorphism, and you're comfortable with the interfaces as used in the Java programming language. You have programmed in an object-oriented language, probably the Java programming language. You have designed object-oriented systems. You are preparing for the "Sun Certified Enterprise Architect for the Java 2 Platform, Enterprise Edition" exam or are otherwise seeking to improve your skills as an architect.There are certainly other profiles for whom this book will be valuable. For example, many managers would find this book useful, provided they have a reasonably technical background, and they will gain sufficient understanding of the processes and values of architecture to allow them to manage effectively.How This Book Is OrganizedThe chapters in this book describe either general topics covered in the exam or one of the key objective groupings of the multiple choice part of the exam. Some of the general chapters provide overall background information and skills, and some relate directly to the assignment.The chapters that relate directly to exam objectives take a consistent form. They start with a description of the objectives and provide background information about the topic. Next is a description of the prerequisite information that we assume you already know. Be careful about these prerequisites, we've tried to to a minimum, and in some cases, there is no prior knowledge assumed, but if there are prerequisites listed, you must ensure that you meet all the prerequisites. After the prerequisite list, the chapters move into the body of the discussion. At this point, you'll find the main descriptions of the issues at hand.After a discussion of the issues, this book reviews the key points contained in the chapter. This will help you learn and review the material because it is a concise listing as opposed to the in-depth description provided in the chapter. If you believe that you already understand the issues in a chapter, you can simply go directly to this list and see if you are familiar with the information in the list. Finally, the chapter presents a number of self-evaluation questions. You should not look at these questions as sample exam questions, although some do take the same format. Generally, they are intended to make you think, and to probe your understanding of the topic. This is much easier to achieve using a broad-based question rather than the more precise exam questions. You should be less concerned about the answers matching your answer, and more concerned about your thought processes covering the same ideas as are discussed in the question. As an example, this book contains questions that use a free-form answer, such as, "what are the issues that would influence a decision about?" You won't see that type of question in the exam, although you will need to outline your decision-making processes and priorities in your assignment submission. When you work through a question of this type, you should get a feeling of "OK, I thought of all those issues" and a feeling of confidence that you understand all of these issues. If you missed something, or if you don't really feel you understand a particular topic, you should be honest with yourself. Taking an honest, professional attitude to your self-judgement is the only way you can get the best from yourself and from this book.About the Case StudyThis book presents a case study in a format that is similar to the assignment. You are presented with use cases, a domain object model, and additional requirements. This format should be familiar to you as an architect. Every system you work on in the real world will have requirements of some sort and it just so happens the exam assignment has chosen to define the requirements in use cases and a domain object model. As the architect for the system, you must provide class diagram(s), component diagram(s), and sequence or collaboration diagrams to communicate your architecture.About the ExamThe exam has three parts, a multiple choice test, an assignment, and a written part in which you discuss specific parts of your assignment.