Exam #310-025: Sun Certified Programmer for Java 2 Platform (SCJP) Vendor Sun Microsystems Status Live since June 15, 2000 Reviewer's Rating "This is the only exam I've ever taken where I was still shaking with nerves at the end." Test Price $150 (U.S.) Who Should Take This Exam? Those who want to be certified as Sun Certified Java Programmers, or move on to Sun's Java Developer certification. What Classes Prepare You? SL-275: Java Programming Language; others. Objectives Click here

Of course, it can't do any of these things unless it's in the hands of a competent professional. This is where Sun's Certified Java Programmer (SCJP) exam comes into play. It will test your knowledge of not only the Java language, but also threads, layout managers and more. If you're looking to become a well-rounded Java programmer (or want to move up to Sun's Developer certification), this is the exam for you.

Exam Basics
The SCJP exam -- now covering the Java 2 Platform -- is aimed at programmers already experienced in using Java. It covers the following topics:

• Declarations and access control
• Flow control and exception handling
• Garbage collection
• Language fundamentals
• Operators and assignments
• Inheritance, overloading and overriding
• Threads
• The java.awt, java.lang and java.util packages

For a complete list of objectives tested, click here.

According to Sun, the exam currently features 59 questions, with a pass rate of 61 percent. The fee is $150 (U.S.), and you have two hours to complete the exam. If you fail and have to retake it, you pay the fee again and you get a different random selection of questions. This means it's going to be just as difficult every time you take it, so it's best to prepare properly and get it right first time.

The SCJP Experience
The exam is administered by Prometric testing centers (www.2test.com). When you arrive at the test center, you have to produce proof of identity -- something with your signature and photograph on it. You'll leave all your belongings in a locker, then you're shown into a cubicle with your computer, on top of which is a camera watching you all through the exam. This way, the testing center ensures sure you don't have any crib sheets, place a call to a friend or send semaphore messages out the window. A little indicator at the side of the screen shows you how much time remains. One nice thing about this exam is that the testing software allows you to review questions you've already answered, or any that you left blank -- in other words, you can go back.

The questions themselves come in three styles:

• Multiple-choice with one correct answer.
• Multiple-choice with several correct answers.
• Questions requiring a typed response.

Many questions involve studying a chunk of code eight to 20 lines long and deciding what the outcome will be -- whether it will compile, produce run-time errors, or its output's numerical value. Each is time-consuming and demands detailed attention; I found that I couldn't relax for a moment during that two hours. In fact, this is the only exam I've ever taken where I was still shaking with nerves at the end.

This is a rigorous exam. For example, with the multiple-choice/multiple-answers questions, all the correct statements must be selected and none of the wrong ones -- otherwise you simply get no credit at all. When I took the exam last year, there were no clues given about how many options you should choose: It could be anything from zero to all. Lucky for you, that's been changed -- the current version now tells you how many to choose so you'll know when to stop sweating and proceed to the next question.

With this exam, you can't rush: Don't assume the first thing that looks correct really is. Always look at the other choices -- you may find one subtly different, but that subtlety is what's going to make the difference as to whether you pick up a vital point or chuck it all away.
At the end of the exam, you'll get an overall score, plus your score for each of the major objective sections. This breakdown helps if you need to brush up your skills for a re-sit or just want to improve after you've passed.

What To Watch Out For
In general, this exam is rather fair, but there are some things that can trip you up. For example, the exam is rather artificial in asking questions about the java.util, lang and awt packages without allowing access to the documentation. You wouldn't do this in real life. But, as these packages are so commonly used, it's actually quite helpful in speeding up your practical programming skills.

Tip: A lot of predefined classes come with the software development kit, and you have to learn your way around them. That way, you can save yourself a lot of time and effort when writing real programs. Related classes are grouped in packages. For example, the java.io packages contain all the classes related to input and output. Packages awt, lang and util are the only ones you need to know for the exam, but others are equally essential for practical work.

You might be surprised to see advanced topics -- such as threads -- in a language-fundamentals exam like the SCJP, but one of the hallmarks of Java is that multi-threading is actually part of the language itself, rather than coming directly from the platform. As a competent Java programmer, you should be able to define and start threads, protect data against corruption when two or more threads try to access it at once, and know how threads can communicate with each other.

This exam also tests your knowledge of layout managers, which are part of the java.awt package. As a SCJP, Sun expects you to know how to break down a complex GUI into a collection of nested panels, each using its own layout manager. You must also master how the layout manager will affect the size and arrangement of components within a panel

Another area to know: Memorize the inheritance hierarchy of exceptions -- otherwise, you won't be able to answer the questions on overriding and catch clauses.
And don't be surprised if you're asked about shift operators. In real life, it's only when you interface with hardware that you use these. Even so, you should know the effect each operator has on the magnitude and sign of the various data types.

How I Prepared
I started my study of Java by sending myself on a purely theoretical training course. Then I dipped into six or more textbooks, practiced some mock exam questions and wrote a few little programs. I practiced the mock questions until I was averaging 80 percent correct and then booked my exam. In the final week before the exam,I read two chapters per day of my exam-revision book and did the tests at end of chapters.

Sun offers a variety of instructor-led courses to teach the fundamentals of Java. Its five-day course, "SL-275: Java Programming Language," is a very good introduction to the language; object orientation and UML; and the tools, facilities and characteristics of Java. If you come from a C++ or other object-oriented background, this course is suitable.

Tip: One of the things you learn in SL-275, though it's not on the exam syllabus, is the javadoc tool. This is a real boon to practical software development. This tool makes it really easy to re-use your own software and keep its documentation up to date. You just "recompile" your source code with the javadoc tool -- it's as quick to bring your documentation up to date as it is to make your final successful compilation of your modified code.

Sun provides other courses catered to those at different starting points:

• SL-110, Java programming for non-programmers.
• SL-210, Migrating to Object Oriented programming with Java technology.
• SL-265, Java Technology for structured programmers.

Unfortunately, none of these courses coincides exactly with the syllabus of the programmer's exam. It's recommended that, after taking the SL-275 course, you spend a full three months with Java before attempting the SCJP. This is a realistic expectation -- you'll need time to digest all the new knowledge enough to be able to see through the subtleties of the questions.

If you have good self-discipline and are working on a budget, you can self-study with books. My favorite is "Complete Java 2 Certification Study Guide, Second Edition" by Simon Roberts, Philip Heller and Michael Ernest (Sybex 2000). There are mock exam questions at the end of every chapter, and the accompanying CD contains an exam engine that will generate a 60-question exam on demand, using a format very similar to the real thing (the fact that this book is partially written by the lead author for the actual exam may have something to do with this). A few of the exam questions have almost trick answers, and this book will help you to get used to the way Sun phrases things. With it, you can bone up well enough to pass the exam without much hands-on work (I'm sure Sun hates me saying that, but this book is that good!). However, the book can get boring, so you're really better off combining it with some practical work. Grab a textbook with a lot of examples programs, run them, experiment and modify them and see what happens (don't neglect to write some programs from scratch, too!). "Java: How to Program," by Deitel and Deitiel, Prentice Hall, is an excellent book for this purpose. It features a lot of programs (all of which work!) on its accompanying CD. Other good books include "SAMS Teach Yourself Java 2 in 21 Days," (but avoid the 24-hour version!) and "Thinking in Java," by Bruce Eckel (Prentice Hall, 2000).

To do your own practical work, you need the Java 2 software development kit. You can download this free from java.sun.com. Also, it often comes on the CD accompanying books. It's easy to install, and you'll soon be up and running.

Several Web sites are useful in preparing for the exam. Start with java.sun.com for live expert chats, forums and tutorials. Next try www.gamelan.com, which has tutorials -- some of them aimed specifically at preparing you for the programmer's exam -- plus quizzes and news items. There's also www.javaranch.com and www.jchq.net, to name a few.

How the Exam Relates to Real Life
Does the exam help train good programmers? I think so. It helped me get a firm, precise foundation knowledge of the language, so now I know what Java can do and I know where to start with a particular problem. I previously learned C and C++ on the job in a haphazard, need-to-know way, and I still feel shaky in my grasp of the fundamentals. I can write a Java program much more quickly than a C++ program because of my better foundation in that language -- all thanks to this exam. Best of luck with your SCJP experience.

What's your take on the SCJP exam? Post your comments below!

More articles by Christine Connolly:

• My Top 10 Tips for Understanding Java's Object-Oriented Characteristics
  
• JSP in Pictures