Why get Java certified?

Learning and jobs reasons tend to be the most common reasons to get a Java certification.

1. If you are new to Java, a Java certification can help you learn Java more deeply and thoroughly. If you are experienced in Java, a certification can do the same for learning what is new in the latest versions of the language. For example, have you mastered text blocks yet? Even the edge cases?
2. If you are looking for a new job, putting Java certification gives you a talking point on your resume. It also gives you deeper knowledge for the interview. If you aren't looking for a job, it can show your employer that you are keeping your skills up to date or even help with a job transfer.
3. If you are using Java at work, doing your job better. By studying for a Java certification, you learn more Java APIs and problems that can occur in your (or teammates) code. This helps you solve problems faster and become more productive.

What certification exams are available?

There are currently a number of active Java certification exams.

1. 1Z0-831: Java SE 25 Developer Professional exam - 50 questions in 120 minutes, passing 68% - For Java 25; the most recent certification exam available.
2. 1Z0-830: Java SE 21 Developer Professional exam - 50 questions in 120 minutes, passing 68% - For Java 21.
3. 1Z0-829: Java SE 17 Developer exam - 50 questions, passing 68% - For Java 17.
4. 1Z0-819: Java SE 11 Developer exam - 50 questions, passing 68% - For Java 11, the exam was launched in two parts like Java 8 (1Z0-815 and 1Z0-816). It was consolidated into a single exam, the 1Z0-819.
5. 1Z0-808: Java SE 8 Programmer I exam - 56 questions, passing 65% - For Java 8, the exam was split into two parts. You earn a certification for each one. . Taking this first half gives you a more basic certification while you work towards the 809.
6. 1Z0-809: Java SE 8 Programmer II exam - 68 questions, passing 65% - This is the second half of the Java 8 exam.
7. 1Z0-811: Java Foundations exam - 60 questions, passing 65% - The foundations exam was introduced for those in Oracle Academy. It is far less common than the other exams. It uses Java 8 as well.

Most people start with one of the latest two (1Z0-831 for Java 25 or 1Z0-830 for Java 21). Some start with the 1Z0-811 if they want to start with an easy certification faster. It is very important to use study materials that match the exam you are studying for. For example, you should target the 1Z0-830 exam if you hold Java 21 materials.

Should I wait for the next version of the certification?

You might have noticed that the exams target Java versions matching the LTS (long term support versions). I recommend taking an exam that is available when you want to start studying rather than waiting for the next version. It typically takes a number of months after the LTS release for the objectives/exam to come out. Then it takes time for updated certification study materials to come out. It's a lot harder to pass the test without study materials.

Additionally, one of the benefits of a faster LTS release cycle is that the language syntax can evolve more rapidly. As a result, taking the exam that matches your study materials is likely to meet your goals and no need to wait for the next exam to come out/study materials to be updated.

What is covered?

Each exam (see links above) has the objectives posted under "review exam topics". There are a number of top level objectives. For example, exam objectives covered in Java 25 ones are:

• Handling Date, Time, Text, Numeric and Boolean Values
• Implementing Program Flow Control Using Decision and Looping Constructs
• Applying Object-Oriented Principles in Java Programs
• Implementing Exception Handling in Java Applications
• Using Arrays and Collections to Store and Retrieve Data
• Processing Data Using Streams and Lambda Expressions
• Packaging and Deploying Java Code
• Implementing Multithreading for Concurrent Code Execution
• Performing Input and Output Operations Using the Java I/O API
• Developing Applications with Localization Support

Then for each one there are more detailed sub-objectives. For example, the streams and lambda one has:

• Use Java object and primitive Streams, including lambda expressions implementing functional interfaces, to create, filter, transform, process, and sort data.
• Perform decomposition, concatenation, reduction, grouping and partitioning, and gather operations on sequential and parallel streams.

Your study materials will give your more details on what you specifically need to know. They will also teach you what you need to learn, point out tricks and practice questions. You should also write lots of code. It's like math; you learn better by doing as you learn!

How to study for the Java 25 certification?

If you subscribe to Oracle University, there is a 40+ hour video class. Since the exam just launched, books are not available yet. There are Java 21 books (see next sections) and CodeRanch provides a table comparing the objectives between the Java 21 and 25 exams.

Regardless of how you chose to study, I recommend the Enthuware mock exams. They are only $10 and you get 20 mock exams! Excellent practice after you study to get ready. The OCP forum at CodeRanch is also a great place to ask questions as you prepare for your certification.

How to study for the Java 21 certification?

If you subscribe to Oracle University, there is a 40+ hour video class. If not, there are two books: Wiley's Sybex imprint (disclosure: I wrote this) and Enthuware's three part series.

Regardless of which option you chose to study, I recommend the Enthuware mock exams. They are only $10 and you get 20 mock exams! Excellent practice after you study to get ready. The OCP forum at CodeRanch is also a great place to ask questions as you prepare for your certification.