Oct 2022

New features between Java 8 and Java 19

Since version 9, Java has new features every 6 months and it’s very hard to keep track of these new changes. Most of the information on the internet describes changes between the last 2 Java versions. However, if you’re in a similar situation as me, you’re not using one of the latest Java versions but a version several releases older.

Then it’s useful to know which new features were added since the version you use now, or between the versions that you use now and the one you want to start using next. Therefore I’ve compiled a table with all new features added since Java 8 for each new Java version and I keep it updated for every newer Java version.

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Jul 2022

Introduction to concurrency and threads in Java web apps

Threads, concurrency, or synchronization are not very easy to understand concepts. When some concurrency is involved in our applications it’s pretty hard to avoid making mistakes. Although Java provides mechanisms to deal with parallel programming, sometimes there are just too many options. And often some essential options are missing. For web applications, Jakarta EE provides a simplified programming model to deal with parallel tasks. But in order to use it effectively and avoid mistakes, you need to understand the basic concepts which I’d like to explain here.

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Nov 2021

Get logged-in user info in Jakarta EE – the simplest way

The security before Java EE 8 / Jakarta EE 8 used to be a bit complicated and confusing. Every specification provided its own way to retrieve information about the logged-in user. The situation greatly improved with the introduction of the Security API that provides a unified way to do that – simply inject the SecurityContext CDI bean.

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Oct 2021

How to properly inject CDI beans into JAX-RS sub-resources

Jakarta REST (JAX-RS) defines it’s own dependency injection using the @Context annotation. REST resources also support CDI injection if you enable CDI on the REST resource class (e.g. using a bean-defining annotation like @RequestScoped).

But injection doesn’t work out of the box on JAX-RS sub-resources. How to create sub-resources so that both injection mechanisms work also in sub-resources? I’ll show you, it’s very easy.

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Aug 2021

Jakarta EE experts at EclipseCon 2021

EclipseCon conference is a great event for all Java developers, especially those who are passionate about and believe in opensource. The conference is scheduled for 26-28 October 2021. I wholeheartedly recommend to attend it. It’s a free online event, you just need to register to attend: https://www.eclipsecon.org/2021

Specifically for users of Jakarta EE it might be even more interesting to attend the Jakarta EE Community Day, which happens the day before the main conference on 25 October 2021. It’s open to all people that register for the main EclipseCon event. There’s a packed agenda centered on the Jakarta EE, MicroProfile and Cloud Native Java communities, including topics like the present and future of MicroProfile and Jakarta EE, and upcoming features in Jakarta Security, Jakarta Concurrency, Jakarta REST, and Jakarta NoSQL.

If you’re interested, I recommend reading an article of Reza Rahman about what’s happening at the Community Day and why to attend it. Or simply go ahead and register for EclipseCon 2021!

Apr 2020

Possible ways to use Arquillian in Jakarta EE TCKs

Recently, we had a discussion how to create a standalone Jakarta Batch test kit (TCK). For most of the committers, it’s pretty natural to use Arquillian to abstracts tests away from how they are executed on an implementation. But Romain proposed an intriguing idea to use plain JUnit5 that got me thinking. And it didn’t stop with thinking. After a few hours of hacking, I’m now able to present a proof of concept and suggest how we could use plain JUnit5 for the TCK and also how containers can be integrated with it using good old Arquillian to avoid reinventing the wheel.

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Jun 2018

Speed Up Services With Reactive API in Java EE 8

This entry is part 1 of 1 in the series Java EE 8 Microservices

Services can often be optimized with asynchronous processing even without changing their behavior towards the outside world. The reason why some services aren’t efficient is that they need to wait for other services to provide a result to continue further. Let’s look how to call external REST services without waiting for them and also do multiple parallel calls independently and combine their results later with a reactive pipeline in Java EE 8.

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Nov 2017

Configure Payara Server passwords in Docker

Answering Stackoverflow questions provides a great feedback for finding out gaps in the official documentation of my favourite opensource tools. One of the questions which I answered here was how to change Payara Server master password in docker container. Obviously, in a standard server installation, this is simple – just use the asadmin change-master-password command, then type the old and new password in to the console and it’s done. Not in docker though, where the configuration has to be automated by a script. The same applies to all infrastructure-as-a-code solutions like Chef or Puppet. So I had to dig deeper into the documentation and experiment a bit.

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Oct 2017

Using HotswapAgent to speed up development

As a Java EE developer, I sometimes envy how fast it’s possible to see the result of a code change in a running application with interpreted languages like PHP or JavaScript. With Java, it’s always necessary to rebuild the source code in a bytecode, which can be then safely updated only by restarting the whole application. And all developers know that restoring the desired state of the application after a fresh restart takes time and is tedious. A while ago I’ve come across an opensource tool called HotswapAgent that speeds up code reloading. (more…)

Aug 2017

Oracle announced to open JavaEE – what to expect in the future?

Last week, Oracle announced their intentions to open Java EE and transfer it to an open source foundation to continue its development in a more open way. I’ve been involved in some email discussions (here and here) and in a conference call organized by Oracle and I want to summarize what I know and expect in the future. I’m also a MicroProfile project member, so I’ll comment on its relation and future benefits to Java EE. (more…)

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