This Saturday we’ve (the Software Craftsmanship in Cracow guys) organized a Code Retreat, right after AgileCE. We’ve invited Corey Haines to join us and facilitate this meetup, and later on even Alexandru Bolboaca AND Maria Diaconu joined us in facilitating the event and so it got even better :-)

Corey doing the introductional Keynote

Before we start, just a quick reminder what a CodeRetreat actually is (for the sake of everyone reading this blog not knowing what the hell I’m so excited about ;-)). The rules are really easy, take a bynch of passionate programmers, put them in a room for 1 whole day and tell them to code the game of life. There are about 6 sessions, where each time you’d pair up with another person and code away. After 45 minutes you have to delete the code you’ve written, then after a 15m pause to talk about your results you find a new pair and code it again from scratch. It’s important to embrace the code deleting part – it’s somewhat like catharsis… :-) No matter how bad (or great) the code you’ve written was, on average in 22.5 minutes it will go away :-)  The idea is to embrace that you most probably won’t finish the problem in time, so you can just focus on honing your skills in TDD, pairing, IDE usage and generale code style and skillz. There’s no better way to learn these skills than to confront them with someone else’s – that way you both can learn new tricks or find out why some ol tricks you used actually suck :-) In the end of the day, you’ve become a better programmer… and will hopefully take these new skills into your workplace and improve the code quality there :-)

Happy hacking!

The response to our CR was really amazing. We’ve had quite a few sponsors – LunarLogic, AppliCake, ABB, Sii… and the PolishJUG helped out as well as it could with organizing the whole thing :-) Oh, and I hope you’ve seen our nice website created by Olga from LLP? The interest from participants was equally big – all places where “sold out” in just about 3 hours… ;-) We where around 50 people in total and I think that’s a perfect number of coders for such an event. Some coded in Java, some in .NET and others in Ruby or Python, oh and there was an Objective-C and Scala team too. One of the nive things during a CR is being able to try out a new language, so the Ruby guys where really overflown by people wanting to try Ryby for example ;-) I’ve spent the rest of my sessions (4/5) coding in Java and just once had to lay hands on Eclipse… ;-) During one session I tried out ruby (ルビ) with Adam from SCKRK, which was fun as I did read some books/articles about it and really enjoyed the BDD that rspec uses. I also noticed that scala test seems to have derrived from it (or the other way arround :p)… :-)

The 2nd room was also full

After two sessions we had nice long lunch, to relinquish our coding skills and ideas (we’ve ordered from thaisty). And then a next set of 3 sessions followed. This time more focused on experimentation etc. For example one session we managed to not use if’s and for’s at all (sigh, upto one place but the time ran out then..). Google Guava was a great help there :-) On another sessions we’ve focused on Mockito and the more advanced mocking techniques such as parameter catching etc… In the end we really knew how much over engeenired it was but nevertheless it was really interesting to learn and play with these thoughts – that’s what CR is about.

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Final Wrap Up

Later on we’ve sent out a questionary on how much you enjoyed the CR and the response was also really positive. We’ll think about coffee next time – promissed. :-)

Stanley just pulled in my quick gallery commit to our website git repo a moment ago, so you can now visit coderetreat.sckrk.com/gallery and look for yourself on the pics :-) They’re fetched from my picasa so if you’d rather download them all from there, please do so :-)

Group Photo

All in all… I’m really happy and proud to have been part of this event. It’s really been one of a kind and I hope all of you feel the same way about it. Well, it would certainly seem so after the opinions on the final wrap up and questionary later on. :-) So, once again, thank you for participating and see you soon on most major coding events :-) (ps: GeeCON is one of them).

This conference review will be a little different from what I’m usually posting. The thing is that ACE was really most about the networking and exchanging ideas with other interesting people. It really felt “open” (no, I won’t be overusing the word “agile” here – don’t worry ;-)). The speaches where also on a very good level and none of them was actually boring – which actually was one of the problems of this years JDD for example. The reason for this is the new session formula – just one track, but very short talks (30m) with no Q/A at the end of each of them. Questions can be asked then later on during the open space sessions.

Paul Klipp @ ACE

The first day was really crazy for me… Just the day before I thought I won’t be going to ACE and had 2 exams scheduled the conference’s first day. Later that evening I’ve discovered that I’ll be able to go, thanks to a last minute quick response from Paul Klipp (thank you!) – and I sure am happy I was able to participate! Well, coming back to this day being “crazy” for me – I had to evacuate from ACE for a little before lunch to go and write one of these exams, and then run back to ACE in order to make it for the Open Space sessions (facilitated by Mike Sutton)… :-) Hopefully I’ve passed it (got a good feeling about it ;-)).

Corey Haines

One interesting thing is that with the open space formula “if it doesn’t happen… it doesn’t happen” and so not all open spaces where full or held using the same formula (well, mine ended up just as a talk among newly met friends :-)). The nice thing is that on the after party the topic I wanted to talk about actually came back to me from another participant and we’ve had a nice talk about it (“hard to convince co workers and how to deal with them”). The answer we came up with was “just do your thing and enjoy it”. It’s a fun effect we discussed on SCKRK once – if someone sees you being happy thanks to doing TDD, they’re more likely to give it a try than you convincing them. (Bear in mind this is a nice approach for people not willing to pair-program or discover new things). So in the end, Mike was right, “no question will be left without an anwser” when sticking to the open space formula.

Andrea Provaglio

I won’t really list which talks I liked the most and which not – as, for one thing, each of them had it’s moments. But the talks certainly worth mentioning where the ones by Corey Haines (the same Corey we’ve organized a Code Retreat with later on this weekend :-)) about what Software Craftsmanship and Agile REALLY are about – “shortening the feedback loop” and, as highlighted in later talks, “continuous improvement”. One cool thing we got to talk about it that I’ve been using Corey’s new app for quite some time now – mercuryapp.com and I recommend you check it out too! I’ve also really enjoyed Andrea Provaglio‘s talk about how to improve one self to enable self organizing at all. I mean, we always talk about it, but there are quite a few problems with self organizing teams if the team is for example judging other team members etc etc. It was a really great talk – which he has already given at GeeCON 2010 but there in a longer format – nevertheless it’s really inspireing and always a pleasure to listen to “as a reminder”.

Paweł Wrzeszcz

There was quite an amount of Kanban sessions, and I grasped a little more about it thanks to these sessions. The most interesting though that came to me was that a Kanban board is more “pull based” (yay, just like most git flows! ;-)) whereas SCRUM is more like “assign this task to this person _now_” . The trick with kanban is marking things as “done” and waiting for them to be pulled to the next phase by other team members. Kanban is very lightweight when compared to SCRUM, which actually has quite a lot of rules to which teams not always stick anyways. During Nick Oostvogel’s talk he mentioned that using SCRUM while a project is still “young” and then switching to kanban for a more effective “bug fixing flow” is also a good idea. I think I agree with this and would like to try it out sometime.

Open Space

The best thing about ACE! was the networking, definitely. I’ve met a whole bunch of new friends, refreshed some relationships. This was really easy as everyone was really open and welcoming – I think this might have been because of both the general atmosphere of ACE and the topics mentioned on it. No hard tech stuff seems to keep people more focused on human interactions :-) Another good thing for socializing was the “Not-So-After Party” which took place after the first day, and not the second one as some conferences organize them. The upside was that more people where able to come since they didn’t have to go back to their hometowns etc. The party ended a little after 3AM for us and I was among the few last participants – we’ve had a great time talking ’bout stuff on this party… :-)

Agile Meetup and Open Space explanation

I’m once again getting carried away with my writing (whoops > 900 words) so even though I’ve barely scratched the surface I’ll be ending this blog post now by inviting you to join me on AgileCE 2012! :-)

PS: Next up will be my summary of the Code Retreat we’ve organized the day after AgileCE, so keep your eyes peeled! :-)

Yup, I’m now an happy owner of an Amazon Kindle. In case you don’t know what it is (…how’s that even possible…?) it’s an ebook reader. One of that kind we’ve been waiting for a loooong time now – with an e-ink display and free internet access etc etc…

Here’s an super quick review of it’s features:

• Amazing e-ink display – Yes, it looks really really good. I was kind of sceptic about it but it has proven to me that it really is a pleasure to read from it. It’s even better than some books – printed on this damn “shiny paper”. So yes, I do see great potential in E-Ink, too bad it’s proprietary.
• NOT an time waster – other than the iPad and it’s concurrence the Kindle will not distract me. No awesome GUI, no shiny buttons. Just a few short cuts (yay for keyboard fans) for just about anything. Finally I’ll just focus and read some books I’ve been trying to start/finish since a long time, but didn’t want to drag them to the uni of some place else (because they’re really big (coding books)).
• No shipping fee for books that I order from the US/UK - I striked this one out as you can see. Why? Because Amazon has just expanded to another 16 countries or so, and thus I wouldn’t have to pay any shipping if I’d order an print book (mainly coding books btw) from the UK. Also this point is for all ebook readers, not just the kindle.
• Free 3G internet connection world wide – although in Poland I do have my phone connected to the web most of the time. While being aboard this may really be useful – It certainly would be welcome during my last Japan trip.
• It also reads images, pdf’s audiobooks doc’s etc. I’ll be using it during my classes a lot, since we often get a lot of PDF’s to be used during our laboratory classes.
• Emailing my Kindle – this is an way to deliver myself (or let someone send me) some document and have it immediately downloaded by the kindle. It also allows converting of normal PDF books to Kindles format, which allows it to scale pages a little better and enables text-to-speech.
• Text-To-Speech is actually not bad! I’ll probably listen to some chapters on my way to work (I’m going alone by car most of the time). And music playback is also a nice touch, I always listen to some ambient or chilloutish stuff while doing anything that involves concentrating.
• Yup it’s Linux (well, but not much GNU I guess…) and Java powered. They’re now testing their SDK (KDK) and will be releasing it quite soon. Although I don’t think the Kindle really needs a whole lot of apps – that’s why I wanted it in the first place: simple + not distractive. And as there will be quotas per user->per kindle->per app on 3G conectivity (100KB per app, I believe) it won’t be coming with some cool rss clients I guess – that’s something I’d definitely like to have on it.

Oh and stop asking me about the iPad and other such devices – I’m not interested. For now, they’re just “yet another time waster” and I really don’t have that much time to buy myself another “time waster”. Most people who are so fond of the iPad and it’s clones are mostly just like “wooo it shines so coool” and “waaaa these animations are so cool”. Yes, i perfectly do see potential in such tablets, but not if they’re so limited that their neither an Kindle (1 purpose, very good at it.) or an laptop replacement – please launch NetBeans or IntelliJ on the iPad and we’ll slowly start talking.

A few downsides:

• Oh, there is one big thing I really don’t like – no GNU/Linux client app for Kindle. Although I do understand that we GNU Guys dont want such software on our platform, it would have been useful…
• It still is a little expensive (well I’m still just a polish student, right?) to buy ebooks for the kindle. It may seem that the books are cheaper than their print counterparts (which is true) but all in all we don’t end up paying less for the books, and are at the risk of loosing them because “amazon had a bad hair day”.

PS: I’ll take it with my to the next JavaCamp (where I’ll be speaking about GIT (warning, it’ll be an extremely “other kind of” presentation)) so if you’re interested feel free to apparoach me and ask me for a quick demo ;-)

PPS: Do you know the book sampled in the first picture? If not, google the first sentence and start reading right now!

PPS: Chunky Bacon!

As this years WARSJawa looked very interesting since it’s been annouced. I immediatly decided to go there – and tried to convince some friends to go with me. In the end, 2 friends came with me: Andrzej Grzesik (from PolishJUG) and Temporal – a LISP/Erlang hacker from my university ;-) We had to ride out at 5:00 to on time (driving so soon in the night really sux), but it was definitely worth it! Now let’s go on with a quick review as always after any conference:

Wojciech Erbetowski z PlayFramework

Wojtek started out the conference with an quick prezi.com presentation but then dived deep into the code and showed us an basic demo of the Play framework in action… I’m not really getting “turned on” by “yet another framework” so I wasn’t all too enthusiastic about it. Some things are really horrible in Play – all views are generated by static methods for example – oh God… Please dont force me to test such an application – you know, with multiple threads… ;-)

All in all: “I won’t be using this one.”

Dariusz [LocK] Łuksza z EGit i przyjaciele

As Darek has taken part in this years Google Summer of Code in the EGit project, he’s the perfect person to give a speech about this plugin. Sadly we encountered an bug in EGit during his presentation and it “broke his flow” a little – which I fully understand. Doing live coding/demos is really hard and I’ve seen a lot of experienced developers/presenters having problems with ther demos. It’s the so called “Weird, this did work last night!” or “Demo-” syndrome… Nothing you can do about it. As LocK’s presentation was mostly about clicking, I wasn’t so happy with it as I’m more of an terminal hero, and like to do all my git commands from the command line. Nevertheless, the EGit plugin seems to have improved quite a lot!

Btw the way… My friends from the PolishJUG have asked me to present about Git during the next JavaCamp (#5), but my presentation (while also being an live demo (oh please don’t allow it to fail… ;-))) will be purely terminal and git command focused. I hope you’ll like that approach…

Paweł Lipiński z “niespodzianką” – w ostatniej chwili za Sławka Sobótkę

This talk was one of the “fun” ones. No hardcore coding action, but lots and lots of fun and comparing everything to Agile. And Software Craftsmanship to a boy that won’t clean up his room etc etc. A very fun talk, but there’s not too much to comment on here, so let’s move on to the meat of this conference:

Marcin Rzewucki z Clojure – podstawowo i praktycznie

“This is the meat.” This is the one presentation that convinced Jacek (Temporal) to go with us to this conference. And I really have to say, it’s also what really tickled my hacker sense looking at the agenda. So, were we let down with just some basic intro..? NO, absolutely no. This presentation was very invofmative, easy to grasp and it turned out to be two presentations in one! The first part by Marcin was an intro to the language and how it functions, along with calling Plain Old Java from it. (Btw, kudos to Marcin for speaking so clearly even though he had some health (throat) problems  at that time)

The second part, which was taken over by Jan Rychter was entirely focused on the practical aspect of coding in Clojure in an commertial application. It was VERY, VERY interesting to see how and why one would use an functional (“very functional”, not just Scala) language to implement some application.

And don’t forget to add Marcin’s blog – http://www.clojureblog.pl/ to your RSS feeds!
Yet another link for starters: http://clojure.org/

Adam Michalik z Co w bajtkodzie piszczy?

You may remember my blog post where I’ve been decompiling string concatenations inside an for loop just to see how much more dump it produces. Adam’s presentation was just about that, decompiling and analyzing the ByteCode. It’s an very fun topic to look into and may lead someone into implementing some language on top of the JVM… :-)

But Adam didn’t stop at just analyzing the ByteCode, in the end he actually coded some fun stuff that the ByteCode allows us to do but the javac compiler doesnt – such as multimethods and calling methods of an interface (invokeinterface) on an Object object… ;-) There were some fun tricks included in his presentation and he seemed really compenent about this matter. “Bit fat 10 points for the man over here ;-)”

Rafał Rusin z Tworzenie zadań przy użyciu komponentów Open Source (Apache HISE, Apache Camel)

While being a little accustomed to (“I know what it is”) with Apache Camel, and seeing some sense in it. I really can’t seem to find any particuilar use case for my for Apache HISE. It’s an WS-Human-Task Spec implementation and aims to… wel… And that’s the problem I had during this presentation, I didn’t quite grasp why I would use it. The general concept of Human Tasks is quite easy to understand, but why I’d need Hise for it is not… One of the reasons I didn’t grasp it may be that we were dead tired after riding +4hours to Warsaw. Having that said, you may want to take a look at their homesite.

Summary

We all really enjoyed everything there in Warsaw, the great people (hooray for networking), food and last but not least the great presentations. During the few presentations we didn’t enjoy we were hacking some of emacs sources (using emacs of course… ;-)), and what a suprise – they’re mostly LISPs (the plugins). That was also a very interesting thing I took from this conference… I’d recommend you go to the next edition ot WarsJawa if you still haven’t been there… It’s even worth +8hours in a car on one day! :-)

Photos and more reviews can be found here:

• http://picasaweb.google.com/bartek.zdanowski/Warsjawa2010#5531326004503230818
• http://blog.japila.pl/2010/10/warsjawa-2010-za-nami-o-javarsovii-2011.html
• http://picasaweb.google.pl/Anna.Mazinska/Warsjawa?authkey=Gv1sRgCNm7mvryj7LcsQE#

PS: Yeah sorry for less links to projects and homepages than I usually include, but I’m kinda very busy right now… :-)

After I came back to Poland this week I had an bazillion of things to do… Now it’s just getting even more but I’ll try survive this.

One additional time-taker this week was this years Java Developers’ Day. In fact, it should have been renamed and I’m very wondered that it wasn’t to: “Java Developer Days” or something like this, as this time the event lasted 2 days, from 8h per day. Of course it’s an paid conference. Having all that said, JDD was the first Java conference I took part in some time ago. I was lucky enough to see the amazing Scott Davis in action and a whole lot of other VERY inspiring talks during the last JDD I’ve seen. So I decided to go there once more, to get inspired once again… and was it worth it this year…? I’m not really sure… But let’s continue with an quick-review:

(There was only one session path on each day – no concurent sessions, thus I attended “all there was”.)

RESTful Java – Bill Burke

I wouldn’t say it was a “bad” presentation. But with practically no coding, and mostly speaking about the core concepts of ROA and REST it wasn’t an interesting nor informative talk. Even more as last year we’ve seen the amazing Scott Davis talking about the same topic (and being an total mind-opener and show-maker). I mean, hey, we’re Java Devs, we know about JAX-RS, right? Or am I just living in my bobble where everyone is well informed about such technology. Well it’s not that new of a technology to start with. REST is everywhere so it was kinda weird to start again with just the basic example use cases. I’d wish Bill would’ve showed a little more complicated scenarios – such as just coding an client (with maybe some nice tricks for it) or working with JSON or custom Object->XML serialization or something, not just the basic “HTTP method = java method mapping” stuff.

Java Programming in a Multicore World – Angelika Langer

This presentation came as an small surprise to us. Angelika indeed seems to know a lot about the internals of the JVM and the presentation did cover some interesting quirks about when memory is “flushed” (let’s call it like that for simplicities sake) so other threads would see an changed state. There was an particiulary interesting note about how transient REALLY works. Although not being an eye-opener, this presentation had some tips and tricks.

Testing the Efficiency of Java Enterprise Applications – Jarosław Błąd

I believe I’ve seen some of Jarosław’s speeches on some recordings, and they kinda keep an steady level, but are not that shocking after you’ve spent some time in JEE and such enviroments. There were some more or less useful sidenotes and some info about “how they did it” which is always interesting to hear… I’d give another 0.5pt to JDD for this one.

The Busy Developer’s Guide to Functional Programming in Java – Ted Neward

Ted did very well with delivering quite an “show” on stage and we had a ton of laughter. The basic idea behind this presentation was to show some basic Functional Progremming concepts CAN be implemented using plain Java. Yeah, with all the verboseness of interfaces and anonymous inner classes but it can be done. As I’ve been hacking a little with python/scala/groovy I felt quite at home with some of the presented methods, whilst I need to note that Ted’s explainations were really good… After this presentation my urge to code in Scala grew even bigger, as most of such functional tasks would be an charm to implement in Scala… Ah well, for the time being we (you :P) can use some library such as Functional Java or Google Guava which both introduce some basic Functional Ideas in an quite nice manner. (BTW: Please do remember that Java’s not really fit to use such mechanisms, but it’s a good idea to get used to it, as we’ll get closures someday, and a LOT of langs are getting more and more functional lately… :-)) I really like Guava and have even given an presentation about it sometime ago… :-) Another point for JDD for this speaker.

Flex in the front, Java in the back: multi-screen RIAs with Adobe AIR and Flex – Piotr Walczyszyn

We’ve all seen Piotr talk about FLEX sometime I guess (well, if you go to a lot conferences I’m sure you have) and if you’re not an FLEX fan it can get a little tiresome. But this time we were positively suprised. His flow though the presentation was quite nice and there weren’t much downtimes. Also he presented the upcoming support for AIR on Android devices (since Android 2.2). As my friend from work didn’t know anything about flex before, the presentation seemed to introduce him quite well into the basic concepts how such an app would work.

Fearless Change: Patterns for Introducing New Ideas – Linda Rising

Linda’s talk was supposed to be the “weird talk” as she called it herself. I think that even thought most of us won’t admitt it, the talk she gave was really important I think. I’ve been trying to introduce an “new idea” in our company ever since “week 1″ and now it seems that we’re getting ready for it… Along with the support of some other coders and our new R&D team. I noticed that all the patterns Linda mentioned, were used by us sometime during this process. It wasn’t like “hey! let’s change everything!”, but just as she said, this process took time and the support of some other team members… Let’s hope we’re able to implement this “new idea” in XSolve – I’d be very happy if we did – everyone together… :-)

Apprenticeship – way to effective professional development – Łukasz Szydło

And we arrived at day 2 of this conference… This presentation was a little like Linda’s on the previous day. Even Łukasz mentioned that he used some of Linda’s patterns in action and showed us how he managed to do some things in his work life… Not so much new ideas, but it was an quite OK talk I guess.

(Łukasz is working for one of the sponsors of JDD. And as you’ll notice – moste of the people presenting on this day were sponsored… I really didn’t like this all that much, since We’ve paid for this conference and didn’t even have an CHOICE but to listen to sponsored talks…? That’s NOT nice.)

Comet enabled application with Lift in 15 minutes – Łukasz Kuczera

Łukasz was talking about Lift on our 4th JavaCamp, but this time all the focus went on on stage coding and Comet. Lift is an quite nice small and simple framework and a nice point to start using Scala if you can’t find any other place for it. Implementing an coment chat was shockingly simple – even though I anticipated that it’ll be “easy” thanks to Scala’s and Lift’s abstrctions around everything. It was a very nice presentation and I liked how it showed both Scala and Lift in action. My coluege from work was also quite amazed at the elegance of Scala (he hasn’t been coding in it before) and we’ve talked a little about it later… A big big point here… :-)

One size won’t fit everyone: on NoSQL in Java – Jarosław Pałka

A quick review of some of the NOSQL databases out there. Jarek mailny covered neo4j and BarkleyDB as well as CouchDB (about which we had an interesting talk during the NOSQL Summer I’ve attended (it’s using map/reduce)). His talk was an very in depth insight into HOW and WHY one would or wouldn’t use NotOnly SQL databases. (I really like the term Not Only SQL by the way, it explains so much of the philosophy in so little words… :-)) Also a nice presentation – espessialy if someone was not well informed about NOSQL databases before. I was also quite happy with it as I wasn’t too familiar with neo4j and always thought that it’s cleanly an very interesting DB for some specific operations (anything graph heavy… ;-)).

Advanced HTTP session management with Oracle Coherence – Michał Kuratczyk

As I’ve been listening to talks about Coherence for over an year now… I kinda went on with hacking some of my stuff on my notebook during this presentation. Coherence is nice, of course as is any Map shared among multiple nodes, but it’s a) uber-expensive b) there are other non-oracle tools that can be used to achieve this goal. Of course, if you really need some heavy weight enterprise support you’d go with Oracle’s solution. BTW, normally Waldemar Kot would be talking about this and Michał seemed to be more like an replacement for Waldek? Also, he was surprised with having to talk in english – which he cleanly didn’t expect.

Technical Debt – Thomas Sundberg

The last presentation on this year’s JDD… Most of the ideas Thomas supplied were already covered by Linda or Łukasz – study groups etc etc. And the “Technical Debt” is basically just an name for how much shitty parts you have in your codebase. I didn’t really like this presentation as it was mostly “all talk and no ‘do’…” but it may have inspired someone to cleanup his code base on next monday etc… ;-)

All in all… The organization was kinda weak (with super chaotic agenda changes), one of the reasons may have been the 1 to 2 day switch, or maybe no money or something like that…? The T-Shirts look bad (it’s quite possible that one might not recognise that it’s an JDD shirt at all…), and did cost extra money… ;-) And the booths were kinda poor. Comparing it to last year’s JDD, it was worse, in many aspects. I think that blowing it up into these 2 days was an bad idea and probably caused a lot of these problems. I believe that Javarsovia was an even bigger and more interesting conference (not even mentioning the uber-awesome GeeCON – I really mean it, the atmosphere and amount of people interaction and networking was much much greater there!) or other fun things like our JavaCamps or NYAC and other initiatives. The poster claimed that JDD is “Poland’s biggest Java Conference” – eeeee….? No, no way. It’s not, just look at Javarsovia or GeeCON, now THAT are the BIG conferences! The good thing is surely that I’ve met some of my friends there and had some nice short talks about Japan and work (no, I didn’t go to the party as I had lot’s of work to be done). ;-)

I’m not entirely sure what to think about this year’s edition. I really loved the previous one, but this time it was kinda “meh” and mostly concerning a lot “basics” and “soft stuff“. This isn’t really what I’m paying for – I’d like some core, good, rock solid technical presentations. Ok, one might say that the agenda is public so I might just wait for it to be filled out ant then judge if it’s worth to go there – but there’s a catch here, the agenda was not final until the very last week before it (and that would cost me around 500-1000PLN – LOL). Ah well, it’s YAC…. ;-)

I’m kinda interested how Radek is enjoying his stay in Berlin at JUDCon, as it’s being held at the exact same time as JDD… ;-) In other news… I’m coding the GeeCON c4p app and I’m hoping you’ll like it when it’s done. Also… we’re starting out with a new series of JavaCamp meetings very soon – can’t wait to see you there!

Till then, Sayonara~

At last I was able to attend one of the NOSQL Summer meetings. It’s topic yesterday was “Paxos made simple” (this paper by Leslie Lamport (wikipedia entry about him)). We also found this document from Google Labs very interesting and usefull during the discussion – Paxos Made Live – An Engineering Perspective (Tushar Chandra, Robert Griesemer, and Joshua Redstone).

For those who don’t know: These NOSQL Summer meetings are entirely self organized and are an form of “reading club” as one might call it. The meeting was amazingly interesting and all the guys where very competent, yet open for any questions.

As we fought through the algorithm’s steps and deciphered possible loopholes and problems – we had a great time. And all this just by discussing the Paxos algorithm. When we encountered something not-understood by all of the group we’d stop and try to think about it. At the end, we’ve had our own set of example values, example conventiuons for “timestamps” etc etc, so the discussion went really well. And as I’ve just found out – we’ve been really near to the exact solution with timestamp assumption – an implementation could possibly use Lamport Timestamps (yup, same author). Well, there were some side-topics about how MySQL replication is just a “bad joke” in more complicated scenarios (well… “complicated” – just an master+slave configuration), but all in all, we focused on Paxos and after finishing the paper – got a little bit smarter… ;-) It’s hard to grasp all the things we’ve been discussing in one “plain old blog post” so I’ll finish by recommending you to go to their next meeting about Chubby – It’s really worth it (ps: please read the discuessed paper before and bring it to the meeting – it’s a “reading club” – remember?). :-)

Oh, and one last thing that would be nice to include in this post… I’ve found and we’ve talked a little about open source implementations of Paxos, and this is what I’ve found: http://hadoop.apache.org/zookeeper/ So if you’d like to see some real code implementing this algorithm, take a look (first read the papers though).

Next week they’ll be meeting to talk about Google’s Chubby – one of the Paxos use-cases we’ve found. Chubby is used by GFS and BigTable, so – even though you may not have heard about it – it’s a “Big Shot”. Sadly I won’t be able to atted since… I’ll be in Japan! “Hell, It’s about time!”* :D
* Starcraft II – opening quote

Łukasz Kuczera – Scala the next Java?

Łukasz’s presentation really did fit the topic and did a really good job in setting the “mood and feel” for the rest of the day. People who didn’t know any scala before – now did know it enough to understand all the code Jonas displayed later, and people who’ve known some scala before – might have got some nice information from this. I really liked it and am now more tha ever convinced of scala’s “perfect fit” nature in the JVM lanugages team. As I was sitting with my friend Temporal – who’s a real Erlang and Lisp hacker ;-) - I’ve got some interesting insights about what scala took from Lisp and later on, what Akka took from Lisp and Erlang. A very good presentation in my opinion. :-)

Jonas Bonér (private site) – Akka: Simpler Scalability, Fault-Tolerance, Concurrency & Remoting through Actors

A very very awesome speech and topic. Akka seems to do Actors and Parallelism very well. Also, thanks to my lisp/erlang friend, I’ve had some amazing insights about where Jonas got some of the implementation ideas. Also, we’d both like to note that some things are done even cleaner in Akka than in Erlang: in erlang you’d pass an actors PID around in order to “link” with another, and the links are always bidirectional. The actor pattern really powerful and scalable from what I’ve seen. It’s also implemented by Vaclav Pech in his GPars library (“Groovy Parallelism”).

This should have been just another presentation in a series of them as Jonas already had presented it on both Scala Days 2010 and GeeCON2010. But! As the present programmers really where into this topic we’ve had a lot of pauses with some chit-chat. A very valuable thing for both akka and our community :-) Too bad that Jonas didn’t have the time to go more into STM, as I still dont really know what it essetialy is “in practice”. Later we got a glimpse of Agents and what they could be useful for. All in all… go checkout the movie – it’s worth your time if you don’t know about parallelism and akka (I guarantee it ;-)): jc4-1-scala-min.mp4

Jonas covered and built upon the previous presentation, and we got to see some more scala in action – feels really natural. The transition from Java->Scala seems to be as painless as the transition from Java->Groovy. That’s a really nice thing I guess. There’s also an Java API for most the things in AKKA – so if you don’t want to adopt Scala in your project – no problems here. If you’d like to read more about AKKA, just goto their website at: http://akkasource.org/ – and yes, it’s open source. :-)

Oh, and if you’d like to see the slides Jonas used: they’re online on his slideshare: http://www.slideshare.net/jboner/akka-scala-days-2010
Also feel free to read this very in-depth post on his blog: Introducing Akka – Simpler Scalability, Fault-Tolerance, Concurrency & Remoting through Actors

Pizza

In the break we had some chats about the usual stuff – programming, companies, and of course a little something about the gaming industry ;-) The pizza was quite tasty – as always – so let’s move on to the next presentation ;-)

Bartosz Kowalewski – Is OSGi ready for enterprise use?

Yet another go with “grasping wtf OSGi is and WTF would I use it?!”. This topic was kinda new to Temporal, as he’s not into JEE Java, where OSGi now seems to be “trendy”. So after a short intro into maven/dependency stuff from me we focused on Bartosz’s presentation. I was immensly happy to see that his thoughts and presentation focused on “what OSGi should solve, and why it sometimes does NOT”. His code examples really cleared up what the problem is, and displayed why OSGi is sometimes a much harder to force to work properly than we’d think it should.

All in all, he described it as an amazing technology to play with, but if one would to use it IRL, with real deadlines etc – one should better know what he’s getting into, as OSGi does solve some things, but in exchange it introduces a lot of more compicated problems. The presentation was really good – as it focused, and really showed how/why OSGi should be awesome, and why sometimes it’s not – most of the time with needless complexity (!).

UPDATE: If your interested in the examples Bartosz has shown during his presentation – download this this zip file that he has made available. It includes the presentation, as well as the sources he used (plus the maven artifacts needed to run the app). Don’t worry if some tests fail – they’re designed to… :-)

Łukasz Kuczera – Lift – simply functional web framework

The last presentation was again Łukasz, continuing in the spirit of this “Scala-flavoured-JavaCamp”, with Lift, an web framework with quite some nice contepts – as view first etc. As it was more of a code-trip, showing the basics of lift, there’s not much to comment on here.

I was kind of disappointed with Lift. It really didn’t seem to be as powerful or mature as Grails of Symfony for example. The “view first” pattern is of course nice and quite well “forced”, but it didn’t strike me to be any different than just Django templates. The CRUD also does not impress someone who’s been using Rail-ish stuff for quite some time. There was not much said about the ORM, but I feel quite comfortable with GORM and the routing system is waaaay overgrown – just look at symfony/grails/rails routing files – they’re short and easy – what I’ve seen in Lift does not seem to be short – it’s quite long and with lots of empty [] etc… I may come back and take a look at lift when I have the time, but it really didn’t impress.

Videos and sources from the meeting

The 4th edition for our JavaCamp was truly amazing in my opinion, and this time, we’ve even got an amazing place, sponsors and great speakers. Have a nice holiday all! And if you didn’t manage to be there live, you can always go to the page bellow and watch the video’s I’ve recorded from the meeting :-)

All videos are temporarily available on my server – here: http://pjug.project13.pl/
I’m hoping to get them up on the java.pl server soon, or better, on parleys.com – but we’ll see about that. :-)

PS: The next camp, won’t be organized so soon – but from what we’ve planed, we’ll be goring into some groovy topics most probably… But don’t take my word for it ;-)

So the long awaited GeeCON 2010 has come to an end yesterday. Of course I was there, and had quite an amazing time there yet again. Here’s, as usually, a small review/roundup of al the three days GeeCON lasted. It’s been really fun, as I was not only attending all the sessions but hanging around with some of the speakers – that was the most fun and interesting part I think.

Day 0 – VeryBerry

After an long 8hour trip by train, we (I was with two friends this time) finally arrived in Poznań. We stayed at the VeryBerry hostel and I’d really like to recomend it to anyone who’d like to stay in Poznań, the prices are low but the service is top notch and the rooms really new and neat :-) After some minor coding, we went to sleep and got read for…

Day 1 – GeeCON University: Gradle Training & JUGs @ Poznań

Gradle Training with Hans Dockter

I was quite interested in Gradle since I’ve seen it in action at SFI (JavaCamp #3 had the same presentation) so I was really happy to be “trained” on it by Gradle inc CEO – Hans Dockter. Apparently they are using it a little (main stuff is still in maven) at SoftwareMind. The training sadly didn’t include as much coding as I’d wish it would, but as Hans said, there’s too much of us (it was the most popular training) and we had 1 day instead of 2 which usually this training would last. The topics where well distrubuted and now all trainees have a really good basic knowlage to start out with gradle. I’m hoping to do this in my soon projects, some ant task usage from within Gradle will be required to build GWT/Vaadin stuff, but hey – the integration is really awesome.

Another fun part was getting home from the University (it’s really awesome by the way) as we took one cab with Hans Dockter and Oliver Gierke (who talked about his Hades project on the 2nd day). We chatted a little in German and dropped them of at their Hotel. Next stop… JUGs meeting~!

JUGs @ Poznań (more info)

This was an short (2h) meeting of the PolishJUG and PoznańJUG. Here we met the rest of my PolishJUG pals, such as Marcin Gadamer and Miroslav Kopecky. And also Geertjan from NetBeans as he was presenting NBPlatform to the JUGs. It was a quite fun session as there was both Chris Aniszyk from Eclipse (and also an OSGi expert) and Geertjan Wielenga with NetBeans Platform – both of which are nice platforms to develop on. The final talk was by Ed Burns in which he presented how the UI enviroment was evolving during the last years and how desktop vs web is now batteling for the users attention. All three would eventually present their talks at the first day of GeeCON – Geertjan dropped in as Ikai Lan replacement as he got really sick and couldn’t do his speech (in case you’re wondering why he’s not listed in the speakers section).

Later we went to a nice Pub called Fuego where we had some interesting conversations with all the speakers and members the Polish and Poznań JUGs… Let’s move on to day 1, shall we..?

Day 2 – GeeCON & Geeky Pool Party

Thorbiörn Fritzon
The Future of Java

The first (and also sponsored ;-)) presentation was done really professional and was mostly about assuring all present programmers that oracle does care about the java community and will continue (even more than sun) to evolve java. Well, this might me be true, but the presentation, while really amazing from the visual side, didn’t really involve more facts than the statement about Java Oracle has released a while ago.

Holly Cummins
Apache Aries: Enterprise OSGi in Action

I hoped to really grasp the whole OSGi concept after this presentation and partially I did. Holly did kind of introduce OSGi to us and tried to show it in action – which sadly didn’t go to well (loosing the war you need to deploy can be quite an problem… ;-)). One thing that Oliver didn’t agree on is that she said that Class loading is the best thing about OSGi, yet as Oliver and some others tweeted – it’s just an enabeler for Services to exist.

Craig L Russell
Easy to Use Highly Available Java Database Access

This was a presentation about the MySQL’s Cluster storage engine. It was interesting to see how such technologies are in fact used from the code – it’s quite easy actually – almost like using an normal MySQL instance. There are some limitations of course – as the lack of relations etc. but if you’d need HA and Fault Tolerance it’s definitely one way you could go.

Some of the talk was about ClusterJ which is an slightly more advanced way to interact with your Cluster from Java… More about it can be read here

Christian Tzolov
Rapid Server Side Java Development Using Spring Roo

Though I didn’t attend this one, I included it in this review in order to say this: Roo ownz (any command line tool that really helps at dev time ownz) :-) I’ve seen some of it in action some time ago, and it’s really helping while developing what you’d call “plain java apps”, without the goodness of Grails generate stuff… If you still haven’t seen it in action: take a look, its definitely worth it. (It’s an development time only tool that like the grails command line app, can really speed up your development time with setting up basic Domain Objects, Persistence etc…)

Eugene Ciurana
The High Availability Non-Stop, Fault-Tolerant Services Tutorial

A very good talk about scalability and availability. Eugene explained to us what the typical bottlenecks could be and how we can cope with them, by scaling up or out – (at last someone clearly defined those two to me). Some of his real live examples where really interesting as one company that switched to an cluster to store their data and not OracleDB what would cost them A LOT… All in all, it was quite educational but sadly – it’s something I won’t be seeing in my upcoming years as “novice developer”.

Ed Burns
JSF 2.0, Myth and Reality

As Ed is one of co-spec lead for the JSF 2.0 (and also “worked on a wide variety of client and server side web technologies since 1994, including NCSA Mosaic, Mozilla, the Sun Java Plugin, Jakarta Tomcat and, most recently JavaServer Faces.”) we were all really interested in his talk. He addmited what they did wrong with JSF 1.x and showed how most of the problems where adressed in the 2.0 release. Is was a quite nice talk, but sadly (and with some maven problems ;-))

Matthias Wessendorf
Practical Comet and JSF

I’ve been really interested in ServerSidePush for a long time, so this was an really fun presentation to watch. There were some implementations and Java Libraries shown. If interested, take a look at Atmosphere on java.net or the Dojo implementation which I’ve been reading about lately. (another nice link) All in all, it’s not quite there yet, and will sometimes have to fall back to polling. Hopefully websockets from HTML5 could be a nice thing to use comet in all the future browsers.

Vaclav Pech
Get ‘em before they get you

Geertjan introduced me to Vaclav Pech sometime during GeeCON and also I’ve been following him on twiiter quite for a while, and I must say the stuff he coded is really impressive – and all his presentations were well prepared and fun :-) That said, let’s move on to this particular session.

A sponsored talk, but nonetheless quite interesting, as Vaclav showed us how to even better utilize all the features that IntelliJ IDEA has. Most of the tools where known to me, but some where new or interesting (it’s quite simple to write your own inspections btw!) The parallel session was Ed Burns with his “Rockstar Programmer” book-talk, Vaclav noticed that Ed’s talk probably has the people who need to become such programmers, while this one has people who already are… ;-) Following that idea, Vaclav went bughunting with us and all the various IDEA tools – it was a nice presentation, with a good link between the audience and him :-)

Geeky Pool Party

In the evening all Geeks where invited to the Black Pool (Pool Club) where one had an occasion to talk with fellow developers and speakers. We had a nice talk with James Williams – not only (but mostly ;-)) about development but also how education works in Poland etc etc… Later I joined the GeeCON and Sun teams at the Pool and played a little with Łukasz (not sure of the name, sorry!?) who recognized me as the “guy from JavaCamps with Shadowman on the laptop” :-) //That said, Shadowman FTW! :-)

Day 3 – GeeCON & GeekTrain back to Cracow

Oliver Gierke
Easing JPA DAO development with Hades

Hades is an really nice way to speed up your DAO development, read more about it here: Synyx Hades. I’ve bee riding a cab with Oliver before and already heard how good of a programmer he seems to be, the presentation just confirmed this. Hades is really well thought out and intuitive to use. Most of the time, all you have to do is write an DAO Interface, that you then use to access your data… Yeah, just an interface – no implementation needed – all the implementing is done by hades. It looks at the interface and tries to guess what an method should be doing, most common prefixes as findBySomething or findAll or other get’s are supported and generic. When you need an custom implementation, you can easily do this as well, and it’s possible to reuse named queries… Really nice, and the upcomming version will be JPA2.0 compatible :-) Big kudos to the Hades team…

The sources used in the presentation can be found on github: http://github.com/olivergierke/hades-geecon

Vaclav Pech
Unleash your processor(s)

A really nice intro into paralelisation – NOT multi threading. Vaclav presented such abstractions as Actors, Agents, Fork/Join and Dataflows… Of course most of this was shown in Groovy as Vaclav is involved in the development of GPars. It’s been quite insightful and now I also know what this AKKA thing is that some people are so fascinated about. Also some Scala and Cloujure examples where really fun to investigate – scala in fact is in many ways so very much elegant and ideal for such sollutions – though Groovy GPars also has me convinced. The withPool 4 {…} is a nice feat for example, and thats just the tip of the iceberg.

Joonas Lehtinen
Vaadin – Rich Web Applications in Server-side Java without Plug-ins or JavaScript

I’ve been trying out vaadin lately and it’s quite nice. Above all, it’s “a GWT that looks good”. The presentation was lead quite profesionally but all in all didn’t really show any “meat” od the framework. One thing I’m concerned about is the (as Hans Dockter likes to call it) “Frameworkitis“, I’m kind of afraid that it might be hard to force Vaadin to do things that the projectant’s didn’t think about… I’m hoping to continue to code my simple rss reader with an vaadin front end – and also I’d like to add some simple JAX-RS powered REST access to it…

James Williams
Game Programming with Groovy

We’ve had a nice talk with James during day1′s pool party. He’s been using Grails lately and is working in the US. His talk was ment to be a more fun/geeky one, and showed simple groovy apps/games, one involving JavaLibrary usage to access the Wiimote sensors. Thus, the code was mostly “looking like java” and not much groovyish was in there.

Charles Nutter
Duby: a Fast, Ruby-like Language for the JVM

I just the last part of this talk, as James didn’t take all the time he had so I went over to look at “this Duby thing”. The best quote I’ve head from GeeCON comes from this talk, it went something like this:

Obviously I’ve been looking at the JVMs source a whole lot. [...] So what’s the neatest feature we all would like in Java…? MultiLineStrings, for christ’s sake!!! [...] And I’ve been looking thought the Java’s sources and there is one single damn if statement, that basically says: “If string, dont allow multiple lines”. And I was like “… You ****!!! For all those years…!! Argh!!!”

Vaclav Pech
Groovy actors and concurrent dataflow with GPars

It was basically the same (well, with more code examples) presentation as the one I’ve seen before, so I switched and went to see Adam Warski and the Checkers Framework.

I also had a small talk after this with Łukasz who recognized me from the JavaCamps and has been presenting on the 1st JC on his Swing/JNLP usage at his work. Sadly I wasn’t into Griffon since then so I couldn’t really give him more tips about it more than that it looks really promising from looking at the examples.

Adam Warski
Static analysis using JSR308 annotations

The checkers framework is a new thing to Java and it basically allows to annotate Types, in a current point in time. Your method can require an @Hashed String and would not compile if passing it an normal String it opens up quite some interesting interactions, some of which Adam has implemented in his TypeState checker which is checking the status of collections if it is safe to read from some place in the code or not – by setting the collections @annotation to certain States (like “you haven’t called isReady, do please dont read from me!”). It’s an interesting way to detect errors in your code before execution time.

Bruno Bossola
Object Oriented for nonbelievers

One of the most fun talks on GeeCON. It was about how we somehow strayed away from what OO used to be, ObjectOriented Design. Nowadays people start out not by building an ObjectModel of their Domain but look for frameworks to use… His talk was there to bring us back to the basics what OO should be about and showed some patterns in use (simple, yet effective). One particulary fun quote from this talk is the last sentence:

Why am I calling this talk “for nonbelievers”? Well… You all agree with me that OODesign is important, but tommorrow you’ll go back to choosing from all those fun frameworks anyways! ;-)

Mark Struberg
JSR-299 Context and Dependency Injection

An very important topic as DI gonna be standarized now… Sadly Mark’s voice was quite monotone and we were all powered out at the time… The presentation as such, was very well prepared and later there was some source shown – that’s how I like it.

End of GeeCON 2010

After some “bye bye” with crew members and speakers, we went to our hostel and back to Cracow – it was a fun event, hope to come back next year. What would I like to be different? Well, more awesome speakers – Scott Davis would be really cool, I’ve seen his talks on JDD09 and they really changed how I think and code. He opened my mind to “Java the Platform” and Groovy and all the other awesome languages. Such speakers would be more than welcome anytime! Oh, and more “hands on”!

GeekTrain back to Cracow, and an surprise meeting :-)

In the train we met some fellow programmer who recognized our GeeCON stuff and most of the trip we where talking about the conference and our studies/work… It was a fun ending for a fun conference… ;-) See you next year!

Amazing days and awesome people

It’s been some amazing days for me during (and before) the NBPTraining. As you probably know already – I’ve been the “one-man-army” behind the organization and basically everything around this training. I got lots of help from various people, such as Dr Jarosław Wąs (from KN Glider) – it wouldn’t have been possible to make this training such an success without his great and very active support. And of course – the PolishJUG, which I’m a proud member of! :-) But one thing I have to admit, Bureaucracy is a horrible thing and really made some things (needlessly…) difficult – thank goodness in the end, we had everything well organized – as Geertjan put it on dZone:

[...] There are also some illustrative pics to share, to give an impression of the group (really large), the trainers (really busy), and the organization (really good) [...]

Day 0: Welcome Dinner

What’s so worth mentioning about the guys just coming here anyway? Well it was a quite trip for some, especially Geertian, who had to come by train which took him about 27hours instead of just coming by car from Prague. All because of Eyjafjoell‘s eruption last week… And Toni and Geertjan were in Oslo at that time, doing a Training for an company (btw nice interview with Gunnar Reinseth) – so we were worried if they’ll be able to come to Poland due to all the flights being cancelled… Anton was lucky and but Geertjan’s original flight got cancelled… Well, he had quite an interesting journey as he called it himself :-) Later when Karol joined us and soon we all went to eat some pierogi and chat a little :-)

Days 1 & 2: The Training

Thanks to dr Wąs everything went smooth and without any problems… Even though some other students also wanted to use the room we had reserved – due to the chaos caused by the tragic plane accident and them wanting to make up for the classes they’ve lost last weekend due to the burial ceremonies… I’m really glad we managed to get the training rolling with absolutely no problems – we were really prepared for everything, along with backup projectors etc ;-)

If you’re not very familiar with the Java World – please note, that the training was NOT about NetBeans IDE. Yeah, we did use NetBeans IDE (there’s some nice little helpers/wizards), but that’s absolutely not a must – NBP is pure Java (just a bunch of jar’s) and XML – so you can use anything you want to code stuff based on NetBeans RCP. That said, the training was about real coding stuff such as patters used in the RCP, use-cases and “ how do I code such a feature  to scale well?”.

The agenda was the basic NetBeans Platform Training as outlined on http://edu.netbeans.org/courses/nbplatform-certified-training/ that’s a good thing, as only a few students actually have used the NetBeans RCP (or even ANY RCP) in their lives. The level of participants was quite diverse, some saw loose coupling in action for the first time in their lives, and others were already planing some advanced use-cases foe the things we were learning. The sources and videos for most of the examples are also hosted on netbeans.edu.pl, so if you want to know what you’ve missed, feel free to download/watch them (if interested in FullHD versions, contact me per email). The Lookup and Nodes/Explorer Views were the most interesting features of the platform I guess. Of course having an full blown app with menus etc out of the box is also nice, but not a “life changer” if it weren’t for those mechanisms. Sadly we didn’t talk about the Lexer API (for parsing languages) but I personally talked with the guys a little about it – and why schielmann was dropped etc… A really fun and interesting insider talk :-) I simply love such conversations…

After the training Geertjan gave away a copy of his book (“Rich Client Programming”), to the person who asked the best, most interesting questions during the course. Of course it was then signed by all the trainers. Sadly I don’t have a picture of the books’ winner, nonetheless – congratulations! After the training I also asked the guys to sign my copy of the book, hurray for signature collectors ;-)

Anyone interested in some of the response I got concerning the training? After the training plenty of you mailed me and thanked via forums etc, here’s a few responses:

przyznaje, na prawde baaaardzo fajne szkolenie

Faktycznie – świetna robota. Wielkie dzięki ;)

Tru. Gj.

[...] nie udalo mi sie zjawic a slyszalem ze bylo super ;/

[...] bedzie problemem jesli przyjde jutro na to szkolenie NetBeans’a? Bo slyszalam ze duzo ciekawych i przydatnych dla mnie rzeczy jest wiec chcialabym sobie posluchac :)

See you next time!

I hope you all enjoined the training – we certainly did. I’ve got some opinions from happy participants, so I guess everyone liked it as much as those did.

If you have anything (opinions, sources or even complaints) feel free to contact me: kmalawski@project13.pl or just leave a comment here :-) Also, when you get your NetBeans Certified Engineer and would like some more promotion for your open source project – let me know and we’ll add a link to it at netbeans.edu.pl!

Some students have already  have started their projects based on the NetBeans Platform – so what are you waiting for?! ;-)

What’s next for me?

Well, I’m going to GeeCON, to learn about Gradle, and tap into facts and myths about JSF and other things (the list of good topics is really long so I wont list them all here, just have a look on your own). The agenda mostly caught up my attecion and I’m really happy to be going there. What’s new for me + conferences is that I don’t have to go alone anymore. I’m going with a friend (some years older) and potentialy another girl – as she won the Google trip to GeeCON… ;-) I’m also really happy to be able to meet Adam Dudczak, thanks to whom the whole NBPT idea got ignited in me and the NetBeans Guys :-) Of course we’ll meet up  with all the PolishJUG members, (Adrian Nowak, Radosław Holewa, Marcin Gadamer and Kuba Dżon) and Miroslav will be comming too – lot’s and lot’s of programming-friends :-) Seems like Toni and Geertjan will also be comming, yay! Yeah, so that’ll be 3 days in May… but that’s not the end of my Java related stuff in May:

Later in May I’ll be on an Spring Source Training. It’s only the “short introductory one”, and I’m well aware that it won’t make me an spring-guru, but an insider insight about Spring, Roo or Grails is also a good thing to have.

By the way, did you notice that the netbeans.edu.pl is running on Grails? I’ll release it’s sources when they’re polished enough~! Viva la free software.

Geertjan, Toni, Konrad (me), Karol

Oh, and for those asking: Sadly I didn’t own an PolishJUG T-Shirt at the time of the training, so I took the most Java related I had – from Java Developers Day. Also a quite nice conference… :-)

Niestety tego samego dnia, około godziny 9:00 doszło do katastrofy polskiego samolutu z b. ważnymi osobami rządowymi i nie tylko Polski… Trudno jest sprawę opisać słowami i chyba każdy wie o czym mowa, także podobnie jak na JavaCampie, pozostawiam to w chwili ciszy i kontynuuję z materiałem…

[...]

Piotr Jagielski – “Testowanie z użyciem obiektów zastępczych”

Świetna prezentacja na której w końcu zobaczyłem EasyMock (okazało się że wcale nie jest taki Easy jakby nazwa sugerowała) Mockito oraz PowerMock w akcji. Jedyne co miałem dotychczas wspólnego z testowaniem przy wykorzystaniu Mock obiektów to ręcznie napisana MockCrosswordGenerator – okazało się że jest to w pełni normalne i porządane czasami podejście do mockowania – także ucieszyłem się że moja domorosła odpowiedź na pytanie “jak to sensownie przetestować + słyszałem coś o mockowaniu ale franeworka to mu tutaj nie trzeba” pod tytułem “a napiszę klasę co implementuje ten interfejs i zwraca gotowce” okazała się być normalnym i słusznym w niektórych sytuacjach podejściem.

Wracając do przedstawianych bibliotek -  Mockito wydaje się faktycznie przyjemny (no i był mocno reklamowanego podczas prezentacji), chyba że znajdę coś lepszego… Groovy wydaje się trochę fajniejszy do takich rzeczy “na szybko”, no ale może już dość pakowania go wszędzie gdzie się da hm hm… Mockito po przedstawionych możliwościach i przyjemności pisania testów w oparciu o niego, jest bardzo przyjemny.

Potem Piotr pokazał jeszcze armatę jaką jest PowerMock… Która po prostu potarfi mockować wszystko – magicznie. Bo jak wiemy niezbyt da się mockowanie zastosować przy metodach statycznych czy metodach/klasach finalnych. PowerMock trochę “czaruje” bytecode’em i nawet takie trudne sytuacje potrafi mockować… Co fajne – buduje on “na” tym co już mockito i easymock zdążyły stworzyć – nie jest to kolejne API które trzeba kuć absolutnie od zera :-)

Prezentacja była na prawdę świetna i chętnie posłuchałbym Piotra ponownie na jakimś innym spotkaniu.

Tomasz Kaczanowski – “Gradle”

Tą prezentację Tomek przedstawiał na tegorocznym Studenckim Festiwalu Informatycznym i akurat na niej miałem okazję być (oraz na prezentacji Jacka Laskowskiego oraz “warsztatach” z GWT… ale o tym post kiedy indziej). Także “nic nowego”, co nie zmienia faktu iż była zarówno wtedy jak i teraz porządnie przygotowana – co na prawdę było widać, oraz prowadzona “z sensem” – jakieś tezy, jakieś zestawienia, przykłady a następnie sprawdzenie co faktycznie Gradle nam daje a czego nie.

Na JavaCamp w przeciwieństwie do SFI było obecnych więcej prawdziwych programistów Java na codzień pracujących z Maven2, oraz będących dobrze poinformowanych o nowościach w Maven3. Dzięki temu prezentację często przerywano i dyskutowano na temat “czy gradle pozwala na XYZ” lub “w Maven też da się ABC” itp. Bardzo mi się to podobało, z dwóch powodów: prezentację już znałem więc powiew świeżości był mile widziany oraz “życiowe” spojrzenie na prezentowany materiał zawsze jest najważniejsze a na “wielkich konferencjach” często unika się takiego spojrzenia. Słowem? Kolejna bardzo dobra prezentacja z dużym zaangażowaniem publiczności.

Waldemar Kot – “Współbieżność w aplikacjach Java EE”

Bardzo bardzo podobną prezentację Waldemar prezentował Java Developers’ Day 2009, gdzie również miałem okazję go posłuchać. Tam prezentacja nazywała się “Asynchroniczność, współbieżność i rozproszone przetwarzanie w Java EE
- przykłady z użyciem technologii middleware Oracle: WebLogic Server,
EclipseLink/TopLink JPA i Coherence” i jak można zgadnąć po nazwie… było trochę “hmmm”. Tym razem, pod prostszą nazwą, i odświeżonym podejściem Waldemar skupił się na pokazaniu nam WorkManager API – de facto standardu w przetwarzaniu równoległym w JEE. Bardzo ganił dziwne podejście ludzi który twierdzą że współbieżności w JEE “się nie da” (pewnie że się da, ale po prostu nie Thread’em droga) lub “a jeśli musisz to użyj JMS” – dziwne podejścia, faktycznie – skoro WorkManager jest tak ładnym i banalnym API… Standaryzacji się niestety wątki w JEE nie doczekały, ale WM jest dobrym i sprawdzonyum rozwiązaniem. No i mamy również w springu: http://static.springsource.org/spring/docs/2.0.x/reference/scheduling.html Więc w sumie zaskoczył mnie że spotykał się z takimi poglądami dot współbieżności a JEE…

Potem mała prezentacja tego co taka współbieżność w efekcie daje – przykładowe odpalanie wątków i zabawa ograniczaniem ThreadPoola z poziomu serwera aplikacyjnego – to samo było na JDD jeśli dobrze pamiętam.

Kolejne demko dotyczyło już Oracle Coherence. Czyli witamy w świecie DataGrid. Jak to najprościej opisać? “Taka Map… rozproszona na 200 serwerów i samoczynnie replikująca się do baz danych z np. opóźnieniem – dramatycznie redukując ilość zapytań SQL.” Oczywiście to nie tylko tyle, ale również dostęp poprzez Java/C++/.NET do jednej i tej samej instancji serwera. Prezentacja była fajna i ciekawa – szkoda że takie cuda dopiero mają sens gdy ma się miliony zapytań dot. danych – ale technologia z pewnością jest bardzo ciekawa – a wydajność “widać”, skalowalność również ogromna… Cud miód i orzeszki. Na tym się coherence oczywiście nie kończy – pomysł wysyłania “kodu do wykonania” (uproszczona nazwa oczywiście…) zamiast pobierania danych, zmiany, i wysłania również jest fajnie wspierana. Zamiast na bazie danych i SQL po prostu pracujemy z API coherence, które pozwala nam tworzyć pewne zapytania – przedstawiony przykład był takim SELECT AVG(…) FROM, ale wykonanym na mapce coherence… Zwyczajne włączenie kolejnego serwera pozwalało drastycznie zmniejszać czas potrzebny na wykonanie takiej operacji – serwery same się dogadują i replikują między sobą dane aby potem wykonać 1 zapytanie (nic nie programujemy co by mówiło o jakiś serwerach) na wszystkich serwerkach na raz – ot takie podejście do współbieżności. Bardzo ciekawa technologia, no ale niestety wielka armata – chciałbym kiedyś z takich strzelać ;-)

Informacja dla zainteresowanych UniversityDay na GeeCONie:

Waldemar Kot będzie przeprowadzał na UniversityDay całodniowe szkolenie z Coherence – więc jeśli Cię to zainteresowało – zapraszamy.
Inna z ścieżej najprawdopodobniej będzie dotyczyć Gradle, także jeśli interesuje cię gradle, miej oko na informacje publikowane na stronie domowej GeeCON.

Pizza jak zawsze – dobra ;-)

Powyższy post napisano na nudnym wykładzie… ;-)