First two EE4J projects

Screen Shot 2017-12-19 at 23.45.11

I am happy to announce that today EclipseLink and Yasson have been transferred under EE4J and officially became first two EE4J projects! EE4J now contains some real Java code and it’s a big step forward!

New projects URLs are:


Committers list, mailing list and forum URLs are not changed.

We are Hiring!

We are hiring experienced developers for working on Java EE / EE4J projects to my team in Prague. Reallocation is possible. To apply click here or contact me directly using Contact page on this web site.

Job description

Are you interested in shaping the future of Java EE?
Do you want to contribute to designing components for cloud?
Feel like participating in the community-driven development of Eclipse?

We are Oracle Java EE team responsible for the development of mature technologies such as JPA/EclipseLink, JAXB, JAXWS, Jersey, Tyrus and new frameworks like JSON-B/Yasson. As we are scaling the team significantly, roles are ranging from mid-senior engineers up to significantly senior engineer.

You will be able to participate and shape the development of next versions of Java EE / EE4J specifications and reference implementations.

Other responsibilities include interaction with external or internal customers, expert groups, participation in the open source community reviews, mailing lists, forums, and blogs, possibility to present the results of your work at recognized industry conferences.

Your Experience

  • BS or MS in Computer Science or equivalent professional experience
  • Solid level programming skills in Java
  • Strong experience with Java EE and standards
  • Experience using and developing RESTful APIs using JAX-RS, JSON
  • Strong understanding of HTTP protocol, WebSocket, SSE, and other web technologies.
  • Expansive knowledge of issues related to building Cloud infrastructures
  • Solid communication skills (+ fluent English)

Ideally, you can also demonstrate:

  • Prior hands-on experience in developing and deploying Microservices solutions on Cloud infrastructure
  • Experience utilizing IaaS and PaaS from Amazon AWS or Google Cloud Services.
  • Experience in working with Docker
  • Experience with the UNIX-like environment (Linux, etc.) shell scripting
  • Experience with building tools such as Maven, Gradle and Ant
  • Experience with Agile development practices (SCRUM)

We offer

  • Possibility to shape the future of Java EE and it’s components
  • Environment of very smart and senior engineers
  • Possibility to influence latest technologies and standards
  • Competitive salary and very interesting benefit package
  • Opportunity to work in a dynamic international team

Yasson 1.0.1 is released

I am pleased to inform you that a new version of Yasson (1.0.1) has been released today.

Bugs fixed:

  • FIXED: [#57] Unexpected behaviour from @jsonbtypeadapter when marking a field bug
  • FIXED: [#48] Serializing ‘naked’ enum throws exception java.lang.IllegalAccessException bug
  • FIXED: [#47] Serialising enum uses toString() method not name() as specified in section 3.9 of specification bug
  • FIXED: [#43] Date format customisation is ignored if custom instantiation is used bug
  • FIXED: [#42] Serializing a map doesn’t use serializers bug
  • FIXED: [#39] Nillable customizations ignore default rules for processing classes bug
  • FIXED: [#34] NullPointerException when @jsonbtransient is applied on property without setter bug


  • Switched to JSON-P 1.1.2
  • Performance improved

The release is available on Maven Central.

Yasson and EclipseLink go to EE4J

I am happy to announce that we are planning to transfer Yasson and EclipseLink projects to EE4J. These will be one of the first projects transferred because they are a part of Eclipse Foundation already. I already posted announcement in EE4J community mailing list here:

The transfer will not affect any committer rights, but it may introduce some changes in web site URL, mailing lists, etc.
I’ll keep you updated about the progress.

Introducing Yasson

I am glad to inform you JSON-B RI and EclipseLink projects have been successfully separated. It was not a union of heart, but more marriage of convenience. Both projects had the same committers. Therefore, JSON-B RI was started in a directory inside EclipseLink project. But when JSON-B RI project started to be more and more mature we started to realize that the idea of hosting it inside EclipseLink project was not so good. These projects have different release cycles and different committers. Currently all JSON-B RI committers are EclipseLink committers, but not vice versa. Also, it can change in future, when more JSONB-RI committers are added.

Continue reading

Java2days 2016

Here are slides from my sessions on java2days conference in Sofia (Bulgaria) which I’ve done together with Werner Keil. I would like to say thanks to all people who attended my talks. Your questions were smart and your ideas were constructive.

As bonus here is a link to a small photo album with night pictures of Sofia I took during my stay there.