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On Tuesday 12th June we’re running an event with a difference. Together with our guest speaker Barry Evans, we’ll spend a couple of hours solving fun Java challenges, getting a clear understanding of what causes the most stressful Java bugs, and having fun eliminating them from our projects.

wXUS8yMB_400x400We’ll use this series of Java puzzles and challenges as a way to learn concepts and save loads of time finding those tricky bugs.

This event is ideal for anyone with an interest in removing the pesky bugs that are a daily stress in their work as Java developers!

Barry is a seasoned web application engineer with over 10 years’ experience developing enterprise applications predominantly in the financial sector. Presently, he is an Oracle Certified Senior Applications Consultant at DubJUG partner Version 1, where he has been using Java SE, Spring, and ORM to build middleware for RIA apps written in Adobe Flex & AS3, Angular JS, and HTML 5.

Ahead of the event we caught up with Barry and found out all about the event and to get his advice for new developers.

1. Who do you think should come along?

I believe that Java developers of all skill levels can take something away from the session. There are challenges on a wide range of features the JDK has to offer; from Strings, to Threads, to OOP, and everything in between.

Newcomers to the language and veteran users of the JDK alike are sure to walk away a better bug hunter. Even if you know the Java language inside out, being able to read a short code snippet and determine the outcome quickly is tricky, but great for honing your skills, and most of all, fun!

2. What do you think are the three most interesting questions that this event will answer?

i. Can I become a better Java developer, and have fun?
ii. Is bug finding a chore… or a joy?
iii. Is there a new feature of the JDK I can use on my current project?

3. Why do you think this presentation is important for people?

It’s important to take some time away from your day to day job as a Java developer, possibly spending most of your time working on large-scale enterprise applications, and have some fun solving trivial problems.

The audience will be working on small coding challenges which makes for a highly interactive session. This introduces a unique approach compared to conventional presentations, which can end up being a one-way conversation between the presenter and the audience.

The Java Challenges turn the focus back on to the audience, and the most successful coders learn from doing, not listening.

4. Any advice for junior developers entering the industry?

Get Certified!

One of the main reasons I am giving this presentation is because I studied for the Java SE 8 OCA & OCP certifications. During that study, I was inspired not just by the technical topics covered, but also by the author’s writing style, and their approach to problem-solving.

My experience on the pathway to certification introduced me to many opportunities I would not normally have had, meeting and collaborating with very talented individuals along the way. Don’t consider becoming Java certified as the end, it is only the beginning.

If you’d like to join us at the event it’s happening on Tuesday 12th June, 18:30 – 21:00 at David Game College, EC3N 2ET and is kindly sponsored by the folks @RecWorks. You can find all the registration details here:

You can find Barry on Twitter: @Bazza_NI

On Tuesday 5th June we’re running a new event focused on Java Memory Leaks, and in particular, solving these in under 10 minutes (sounds good to us!). We’ll be using a consistent methodology to identify whether you have a heap memory leak, analysing the memory to identify the leak, and determining the cause.

JSWe’re delighted that we’ll be joined at the event by Jack Shirazi from the Performance and Reliability team at Alongside his role at, Jack is the founder of and author of Java Performance Tuning (O’Reilly); he’s been an official Java Champion since 2005 and an LJC member since 2009. As well as authoring his popular book, and contributing to several other books, Jack has published over 60 articles on Java performance for various sites and magazines; over 200 newsletters for over 15 years; and, with these newsletters published around 10,000 Java performance and memory related tips.

Ahead of the event we caught up with Jack; he told us why the session is important, what questions we can expect to learn the answers to and gave us his advice for new developers.

1. Who do you think should come along?

Any Java developer of any level. I provide sufficient detail for any level of developer and this talk shows how to solve a problem that is intermittent, so even if you’ve analysed heaps before it’s useful to get a different point of view and a refresher

2. What do you think are the three most interesting questions that this event will answer?

The event answers: what process you should follow for analysing any Java memory leak; which tools are most useful for analysing Java heap leaks; and how you can identify that you have a leak before (as well as after) a leak becomes an issue.

3. Why do you think this presentation is important for people?

Memory leaks are one of the most common causes of downtime/server crashes/service failure. But, at least for heap leaks, they’re a solved problem – you just need to know what to do about them. But leaks don’t happen often enough that every Java developer will have or remember the skillset to solve the problem quickly. What I’m providing is a step-by-step procedure that you can easily understand then forget about until you need it – then just quickly refresh yourself in minutes and apply to solve the issue very quickly.

4. Any advice for junior developers entering the industry?

Come to this session and add this to your toolset. Then remind yourself before you have an interview, experience of fixing a memory leak is a cool thing to know for interviews.

If you’d like to join us at the event it’s on 5th June, 18:30 – 20:30 at WeWork Old Street, N1 6DR. The event is kindly being sponsored by the folks at Gridgain, WeWork Old Street and RecWorks. You can find all the registration details here:

What’s Jakarta EE?

Over on Jakarta EE you’ll see our new LJC logo as a Participant member.  This blog post details what Jakarta EE is and what the LJC hopes to achieve within its community!

Jakarta EE is the new brand name for Java EE. For those who missed it, the Java EE platform was recently donated to the Eclipse Foundation (as Eclipse EE4J), the FAQ gives the background to this.

The existing Java EE 8 platform is being migrated to the Eclipse Foundation.  There’s a lot of new build farm activity taking place and the end goals for 2018 are:

  • Q3 2018 – Release Java EE 8.0 by the Eclipse Foundation.
  • Q4 2018 – Release Jakarta EE 8.0 projects (which will be identical code wise to Java EE 8.0) by the Eclipse Foundation.

Both of these releases will be certified against the appropriate TCKs (which are also being open sourced and donated to Eclipse).

In parallel the community at large is looking to the future of Java for enterprise developers.  A future which is lightweight, fast, cloud native and micro services based.  This work has already started and vibrant discussions (for example, around the role of the Servlet container and what types of profiles make sense in a modern world) are taking place on several mailing lists. We highly recommend you sign up to the lists and join in!

LJC’s role in Jakarta EE

The LJC currently holds technical, legal/oversight and advocacy roles at the Java Community Process (JCP) which is the existing standards body for Java EE today.  We hope to continue serving the interests of the day to day Java developer in those capacities at Jakarta EE and have nominated ourselves for the corresponding working groups (Steering, Specification and Marketing).

Next Steps

Are you a day to day Java developer then please come and join us on mailing lists and have your voice heard.  If you’re unsure on what’s going on or are nervous about speaking up, then contact us at the LJC and we’ll be happy to help.


Martijn (on behalf of the LJC Standards Committee)

In case you’ve not been along to one of their events yet, or you’re entirely new to what they do, we wanted to draw your attention to the London In-Memory Computing Meetup. The group is open to everyone and is aimed at those already working with distributed systems or interested in doing so.


We caught up with Tom Diedrich, Director of Community Engagement at GridGain and one of the organisers of the Meetup. Tom told us about why the group was founded, their aims, future plans and gave us his advice for new developers.

What can you tell us about the London In-Memory Computing Meetup? Why did you set it up and why should people join?

I’m one of the organizers of the London In-Memory Computing Meetup, we founded it a couple months ago because we saw an unmet need. The need for a venue for data scientists, database architects, software developers, CTOs — and everyone else — using or interested in learning more about in-memory computing, Big Data, Fast Data, IoT and HPC solutions. This includes use cases, best practices, and more. It may be of interest to you if you are already working with distributed systems, planning or interested in doing so.

What about the future – What is your longer term vision for the group? Can you give us any spoilers about what to expect?

Well, this group is open to everyone and we’ve already had leading in-memory computing experts from Oracle, GridGain and VoltDB speak at the London meetup. My longer-term vision for the group is to have users share their challenges, successes and lessons learned from the trenches.

On the larger scale I’d love to grow awareness about in-memory computing in general. And this meetup will be showcasing, on a regular monthly cadence, the latest news in this rapidly growing ecosystem. So attending these meetups gives members an advantage in that they are informed about not only what’s currently available, but also what is coming up from vendors and users (companies using these technologies) from around the world.

I also see the meetups as a way of drawing attention to the annual In-Memory Computing Summit Europe conferences. The next one will be in London June 25-26. The conference is a natural extension of the London In-Memory Computing Meetup.

Obviously being in a community engagement role you meet with loads of the industries best developers – from your experience what advice would you have for more junior developers about how to get the best out of their career?

I’d recommend that they join the open-source Apache Ignite community, download the latest version and start by saying “Hello” to everyone in the community via the dev mailing list. The project has a very friendly and active group and it’s the perfect place for junior developers to learn. The volunteers are a very nurturing bunch and some of the best developers in the world.

For more information, please visit the London In-Memory Computing Meetup page –

On Thursday 24th May, we’re running an event where we’ll be discussing Upcoming Java Language Changes. We’re delighted to welcome Stephen Colebourne, Engineering Lead, Platform at OpenGamma, the creators of Strata.
Specifically, we’ll be considering what Java language changes are on their way and how will they make your coding life easier?

We’ll also take a look at a range of new features being developed by Project Amber and Project Valhalla to get a good overview of Java’s future. Come along and be prepared to give your opinions on the new features!

Ahead of the event we had a chat with Stephen; he gave us his view of why the event is important, who should join us and some tips for junior programmers.

1.Who do you think should come along?

The talk is a sneak peek into the future of the Java language, where plans exist but nothing is fixed. If you actively code Java and are interested in how the language is going to get better, this is your opportunity to see and think about the future. I might well take some straw polls on the more controversial ideas too!

2. What do you think are the three most interesting questions that this event will answer?

What language changes are coming, how will they work in practice, and
are the right design choices being made?

3. Why do you think this presentation is important for people?

While many teams have been slow to adopt new versions of Java in the past, Oracle is trying to reduce that flexibility by reducing the number of overlapping supported versions. As such, you may end up using these new language features sooner than you might have thought you would!

4. Any advice for junior programmers entering the industry?

Being a software engineer is about much more than just writing code. It’s about the bigger picture, including maintainability, quality consistency and knowing what trade- offs to make. Take the time to listen to those around you and review your own work – that self – awareness will be key to success.

If you’d like to join us at the event it’s happening on Thursday 24th May, 18:30 – 21:00 at David Game College, EC3N 2ET and is kindly sponsored by the folks @RecWorks. You can find all the registration details here:

If you’d like to, you can also find Stephen on Twitter: @jodastephen

On Wednesday 9th May, we’re running an evening of presentations and live demos, all focused on Reactive Microservices with Micronaut and Open Cloud-Native Java. In our first talk, Graham Charters will give a presentation and live demonstration of how the MicroProfile initiative helps you build cloud-native Java microservices on open source, open standard APIs and, avoid lock-in to a single company. Then, Alvaro Sanchez-Mariscal will be discussing Reactive Microservices with Micronaut.

In preparation for the event we caught up with Graham and Alvaro. An IBM Senior Technical Staff Member and WebSphere Applications Server Developer Advocacy Lead, Graham takes a keen interest in emerging technologies and practices, and in particular programming models. His past exploits include establishing and contributing to open source projects at PHP and Apache; and participation in, and leading, industry standards at OASIS and the OSGi Alliance.

Alvaro Sanchez-Mariscal is a passionate developer and agile enthusiast with over 18 years’ experience. He now works as a Software Engineer at Object Computing (OCI), the company leading Groovy, Grails and Micronaut open-source development. Before working at OCI, Álvaro gained a wealth of experience across various industries and businesses; from gambling games to fintech, founding his own company, and working at organisations such as IBM BCS, BEA Systems and Sun Microsystems. Álvaro is also a speaker at conferences including GeeCON, JavaLand, JavaZone and Codemotion. You can find him on Twitter @alvaro_sanchez They gave us a summary of their ambitions for the event, the latest technology and words of wisdom for junior programmers.

1. Who do you think should come along?

GC – This talk should be of interest to Java Developers and Architects looking to develop, deploy and manage modern cloud-native Java microservices. The technologies the talk will focus on are the result of broad industry vendor and user collaboration. They also benefit from having multiple implementations, which means broader input to the design, and greater choice for users.

ASM- Micronaut is a brand new framework for the JVM, so we don’t expect any prior knowledge. Any Java developer is welcome!

2. What do you think are the three most interesting questions that this event will answer?

GC – The first question this talk will answer is, what is cloud-native, how did we get there, and what to look for in an environment to help me? Okay, maybe that’s three questions in one. Understanding how the industry evolved to cloud-native and the characteristics is an important foundation to choosing the right technologies and increasing the chances of success when embarking on a cloud-native journey.

The second question this talk will answer is, what is MicroProfile and how does it help me address the challenges of cloud-native? Based on the understanding established in answering the first question, this talk will introduce the MicroProfile technologies and, along with the use of demos, show how each helps in the development and management of cloud-native applications.

The third question this talk will answer, and some (ok, not many) would say the most important, is whether or not cloud-native should be hyphenated.

ASM – As we are introducing a new technology, the session will give the audience an idea of what Micronaut is and how can they use it in their projects.

They will also learn about Micronaut features that are similar to the ones in other frameworks like Spring and Grails. They should feel at home with Micronaut. Finally, attendees should understand that by using Micronaut they get the best of two worlds: the developer experience and productivity of frameworks like Spring Boot or Grails, and the performance of a compile-time reactive framework based on Netty.

3. Why do you think this presentation is important for people?

GC – As an industry we’ve made huge advances in how we deliver solutions, for example through Agile, DevOps Cloud and Microservices. These advances are the cornerstones of cloud-native. What is sometimes not immediately clear, is what this means in terms of the resulting impacts on how we develop, deploy and manage these modern cloud-native applications. This presentation will help people gain an appreciation of the new challenges and offer open technology choices for how to address them.

ASM – Micronaut was first announced in February and is still not yet public. We are still polishing some things before the first public milestone, which will be published in a matter of weeks. This is a unique opportunity to learn about it!

4. Any advice for junior programmers entering the industry?

GC – My advice to junior programmers entering the industry would be to not be afraid to ask questions; take every opportunity to learn something new. A strong technical foundation will stand you in good stead for the future. Lastly, understand what you enjoy and what motivates you and don’t lose sight of that as you seek to progress your career. If programming is what gives you the buzz, be the best programmer you can be.

ASM – The JVM ecosystem is quite crowded with excellent frameworks and sometimes the number of options are overwhelming. In my opinion, what makes the difference between a good developer and a great one is the ability to judge which technology is the best choice to solve a particular problem. To get this skill they should constantly learn about new technologies. Meetups like this at the LJC are a very convenient way to learn.

Reactive Microservices with Micronaut & Open Cloud-Native Java is happening on 9th May, 18:00 – 21:00 at IBM UK, SE1 9PZ. If you’d like to join us, please register here:


If you don’t already know, jPrime’s 4th conference at Sofia Tech Park, Bulgaria is coming up in less than a month (29th and 30th May). For those who are new to jPrime, it’s a conference focused on Java, various languages on the JVM, mobile, web and best practices. It’s run by the Bulgarian Java User Group and backed by some major businesses. Visitors have the opportunity to listen to some of the best international speakers, as well as presenters from Bulgaria and the Balkans. It’s not all work though… there’s also plenty of time for hacking, networking and fun.

In case you can’t tell, we’re a tad excited about jPrime. Ahead of the event we caught up with one of the organisers Ivan St Ivanov who gave us the lowdown on all things jPrime.

Ivan is the Co-Founder and Senior Programmer at VIDA Software, he also does a variety of consultancy roles, teaches Java and Microservices courses, is an active JUG member and is studying for a PhD in the field of Cloud Multi-Tenancy… we’re seriously impressed.

Here’s what we learnt:

  • jPrime is organised by a group of true enthusiasts – all profits go back into the next year’s JUG events, the organisers do it for the love of it.
  • Now in its 4th year, the conference has grown into a 2-day event with over 700 attendees.
  • The organisers come with a massive range of interests and areas of expertise. There are those that are most interested in the current hype (e.g. hmm, Kotlin, Spring 5 + Reactor, Blockchain); there are also people (Ivan being one of them) that are evangelical about the MicroProfile, and another lead who is active in the OSGi community.
  • There’s a jam-packed agenda, far too many to list, but safe to say, all things Java, languages on the JVM, mobile, web and best practices are explored by some excellent speakers.

And if that’s not enough…

  • The weather in Sofia around jPrime is typically beautiful so it’s a great opportunity to get out and explore the beautiful capital of Bulgaria. It has a long ancient history, so there’s plenty to see outside of the conference.

We managed to get our hands on some tickets for jPrime, and in the spirit of sharing the love we’d like to give them away. If you’d like to be in with a chance of winning a ticket to this year’s conference, you can enter the raffle here – You can see all the details, including the agenda for jPrime here: and you can find Ivan on Twitter at @ivan_stefanov

What is the LJC

The London Java Community (LJC) is a group of Java Enthusiasts who are interested in benefiting from shared knowledge in the industry. Through our forum and regular meetings you can keep in touch with the latest industry developments, learn new Java (& other JVM) technologies, meet other developers, discuss technical/non technical issues and network further throughout the Java Community.