Oracle's Java 25th anniversary offer on OCP Java 11 Developer certification exam (1Z0-819) that allowed one to take the exam at a highly reduced price of $25 is now offer. Hope they extend it but, as of now, there is no news on that. It is back to its regular price of $250 (depends on your country or any other promotional offer)!

Since it is a tough and an expensive exam and since we get many questions regarding how to go about it, in this article, we present a couple of preparation strategies for passing this exam on first try.

How much time do I need to pass the Java Certification Exam?

The first thing people ask is how much time do they need to allocate to prepare for the Java Certification Exam. This is really a tough question to answer because it depends on your current Java knowledge and expertise. This exam covers a wide range of basic and advanced topics and even if you are an experienced Java developer you cannot expect to pass it without thorough preparation. At this same time, this exam requires you to be extremely good with Java fundamentals such as objects and references, polymorphism, equality, arrays, lambda expressions, and such. So, if you have learnt Java from a good book earlier, then it should not take you much time time to learn the advanced topics that are mostly information based such as modules, securtiy, and annotations.
Still, if you are looking for some numbers to plan your preparation, here is what we believe is the time required to prepare for Java 11 certification exam:

1. For Java newbie (0 to 1 year experience): 6 months to 1 year. This exam covers a lot of ground and it is better if you don't rush it. You will not only need to read up a lot of stuff but also memorize the APIs. You need to get comfortable reading and writing Java code because most of the questions on the exam are code based. If you can't read and comprehend code fast, you will not be able to go through all the questions in the exam. You will definitely need to go through a good book, write code, and take mock exams.
   
2. For Junior Java Developer (1 to 3 year experience): 3 to 6 months. If you have been developing with Java for some time, you are already familiar with the syntax and are comfortable writing and browsing Java code. This will help you compile the code "mentally". You will also be able to related to the exam style code problems better.
   
3. For Senior Java Developer (3+ year experience): 1 to 3 months. You already know the tough parts of Java such as the collections API, concurrency, lambda expressions/method references, JDBC, and File I/O. You are comfortable looking up and reading JavaDoc API documentation to understand what a class or its methods do. You are also not afraid to use the Java Language Specification to find out the answers to Java fundamentals. You know about that boundary conditions and "exceptions to the rule" exist and are watchful of them already. If you have been seriously developing Java applications for the past three years, you will not have much trouble absorbing the new material and getting into the mode of answering multiple choice questions.
   

The above timelines are only an approximation. Every person is different and everyone learns at their own pace. So, there is no fixed rule. The best way to find our how much time you need would be to take a couple of mock exams and see how you score. See the kind of mistakes that you make and the kind of information base that you lack. From our experience of training people, we can tell you that if you are able to score above 50% in your first mock exam without preparation, you won't need more than a couple of months to get ready for the exam.

Do I need books to prepare?

1. There is currently no book specifically targetting 1z0-819 exam. Since the 1Z0-819 exam was kind of made by combining the two older Java 11 exams (1Z0-815 and 1Z0-816), the books meant for those exams are applicable for the 1Z0-819 exam.
2. The books are quite expensive (almost $50 for printed copies!) and may not be as useful after passing the exam. So, it would be good if one could do without them.

1. Create and use private, default, and static methods of intearfaces
2. Create functional interfaces
   
3. Use lambda expressions with type inferencing ( See this and this article. )
   
4. Migration to Modular Application - Section 3 of The State of Module System (Read carefully)
5. Modular services - Section 4 of The State of Module System (Read carefully)
6. Serialization - Read Chapters 1, 2, and 3 of Serialization Spec.
7. Security - Read Full Secure Coding Guidelines.
8. JDBC - Any book will do. Focus on PreparedStatement, how to commit/rollback. Ignore RowSet related topics.
   
9. Formatting - Date formatting has two different methods. Using the old java.text package and using the new java.time.format package.  Not clear which one they are focussing on but there are questions on java.time.format.DateTimeFormatter for sure. Either way, go through the predefined formatters and pattern strings given in DateTimeFormatter API JavaDoc.
10. Annotations - Sufficient to go through this trail.
    

For experienced developers