My OCPJ8 Book is published!

My study guide for the OCPJ 8 certification is finally published.

I started the book in last July and everything was going fine, but from September to December, a complicated project attracted all my time and attention, making a significant delay in writing the book.

I got back to the book in February and didn’t stop until I finish it six days ago, releasing three or four chapters per week. The exam covers a lot of topics and producing the book took me a lot of effort, I certainly underestimated the process of writing a full study guide.

I don’t consider myself such a good writer (I still have a lot to learn and, even tough I use it every day, English it’s not my first language), and even if it is not perfect, I’m proud of the final result.

Being an independent author is hard, so it occurred to me that by making the book free for everyone to read online I could reach a lot of people and get help to improve the book.

And so I did it. You can read the book for free at:

It’s hosted on Github:

So you can fork it, modify it, and create pull requests.

If you like it, you can buy the physical book from Amazon (and its Kindle version) or as an EPUB/PDF in other stores so you can support me. The links for buying are on the book’s site or here.

Now that I have finished this project, I can work on other pending projects that I have. Here are some that I have in mind:

  • An online exam simulator for the Java programmer’s certifications.
  • Some apps for iOS and Android using the Ionic framework.
  • Finish
  • I’m a big fan of the Head First book series, so I want to write a book in that fashion (for Kotlin, maybe? I have my eyes on that language).
  • Learn to use some front-end technologies like Gulp, Grunt, Browserify, etc.
Got any questions or comments? Drop me a message on Twitter (@eh3rrera).