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.

1

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).

As I’m coding quite a lot GWT and JS has also become quite powerfull in the last years I enlisted the training to learn more about JS optimalization and add some more tricks to my toolbox. Also some real life use scenarios would be very welcome. Turns out Tanadu (a polish “heroes-like” browser game) was implemented 100% in plain JS. Which is quite shocking and as we later agreed on developing such code can really be a pain in the neck. “Use GWT” would be my anwser to such an use case I guess – you wouldn’t loose the refactoring tooling Java gives you and could still fallback to JSNI if really needed. Did the “training” meet my expectations? Yup. Want more details? Read on… :-)

It was really fun and I’ve even (and unexpectedly) met a friend of mine with whom (and one other developer) we’ve paired up and were coding a JS Mortal Kombat in JavaScript for those two days. We’ve learnt how to use CSS3 *-animation, *- transition and other cool new features (well, most of them “webkit only” but very cool nevertheless). Then we’ve coded a little and went on to dinner ate Jeff’s where I’ve lead the group to :-) Sadly dinner took a little too much time and we had less time to code than Poznań during their meeting a few weeks ago.

By the way… MVC in JavaScript is quite weird (hey, most of the teams ended up with GodObjects anyways! ;-)), as is any acting “hey, let’s just say we can have classess and inherit them blabla…”. We’ve seen quite a few examples on how to emulate OOP in JavaScript which was both: really weird and interesting at the same time. In the end, the thought “if you have no type system, in the end you develop your own” seems really true here. I believe this was said by someone from twitter about their Ruby code, which had a hell lot of assertions in it just to be sure “abc is really of type AbcType”. That’s why I’m more for Scalas apparoach than Groovy’s or Javascript/Ruby/Php, but I’m not that advanced in Scala yet to judge it as “super perfect”… ;-)

MK in Javascript using Node.js

On the next day we implemented the serverside stuff, using node.js and socket.io for the clientside wich worked really well I have to addmit. Although I’m still wondering how I’d handle auth/security to be _really_ secure using such server instances (“nodes” ;-))… Finally our game had a very nice and developed state machine for all basic mortal kombat moves (including high/low punch etc, how much such state is blocking and which sprite to use for it, jumping etc.). As this state manipulation took most of our time, our server didn’t support an infinite number of players as some other implementations did but as a trade off they didn’t have any combo/move logic in their games :-) Of course the game was playable (well, “almost playable” – both players think they’re “on the left”, but we’d fix that very quick if needed… ;-)). A quick finishing talk touched some performance tweaks – quite some we should have used in mSejf etc – so I feel a little smarter than before :-) Sadly we didn’t talk too much about TDD using JavaScript which may be really a good idea (ugh this loose typing can make you mad sometimes… ;-)).

Our mortal kombat game ;-)

What could be definitely improved is the internet connection (well, “organization” as a whole I guess) as we had quite a lot problems with it (choose a hotel which is no noob in terms of IT meetings :-)) and the lead’s knowlage about git. Since it’s quite an deep tool, and we’re not here to focus on it but on JavaScript some quick info about how to use it and more developers who aren’t using it the first time in their lifes would have been really helpful. But fear not, I’ve helped out all the teams with learning git and all merges, push/pull flows and other weird problems :-) So it became quite an hybrid training where some of the participants learnt quite a lot about git :-) Some may actually like it in spite of the difficulties we encountered in our very chaotic flow during our hack sessions… :-) On the other hand, any way of introducing git to new people is a good thing, but I fear some may expierience some discomfort/distrust to a tool they’ve just “learnt” on a “fly by basis”, from… well, me – another participant. ;-)

From my perspective it was a great and fun meeting and I’d like to attend more such meetings, sharing the same  formula, or slightly improved. What I loved was of course the hacking and fun of working in a team + teaching people git… :-) If you’re hungry for some team coding you may want to checkout one of the upcomming meetings or wait for SCKRKs + PolishJUGs “Code Retreat” that we’ll be announcing really soon… :-)

PS: I’ve pushed our game implementation (less than 8h of real coding (rest of the time was talking/presentations/eating etc ;-)) to github, here: https://github.com/ktoso/mk-javascript so you may want to take a look. Event out of pure curiosity :-)

Łukasz Lenart – “Nie samym kodem programista żyje”

Łukasz’s presentation was not a technical one this time. He talked about how to be/become an effective programmer. A nice tip he noted was to carry a notebook and note your ideas in it – i sometimes try to but did find myself forgetting some “amazing idea” due to the lack of discipline in carring such notebook (yeah, an paper-notebook… :-)) so it’s definitely something worth reminding. He also talked a little about Kaizen, ZenToDone and the Pomodoro Technique which all kinda share the same idea but explain it a little bit differently. I also was quite happy to find out that I’m not the only one that gets slown down in development when actually being in the company – with lots of stuff happening around me. Admit it – we all work more productive when there’s noone bugging us ;-)

The most notable tips where the “alone-zone” (as explained in REWORK (good book, I recommend it)) which is really great and I love it, but sometimes it’s hard to enforce – coding is usualy team work, ain’t it..? Using multiple desktops – and monitors at best, to seperate your work space from fun space. Cutting oneself off from the internet is, while extreme, very effective by the way. I noticed it quite a few times – there’s simply nothing distracting you – same goes for anything that might take your attention. By the way, I’m not really convinced about Pomodoro – what if you get into an v. nice flow and then the pomodoro snaps you out of it? I guess it may be more targeted at people working at bigger companies – not as myself in an small nice team and nowadays, mostly from home.

All in all he warmed up the audience perfectly and let’s hope some of theese tips help us become better programmers… :-)

• //TODO: watch on parleys.com
• //TODO: download slides
• download video

Konrad Malawski – “Git (tak. po prostu.)”

The PJUG guys asked me to tell a little about git and I happily agreed to do it – thus, my first “public presentation”. Firstly I’d like to explain why the slides where so “weird”. It’s because I wanted them to be something like an “break”, and most of the session was live terminal typing. They were all hand drawn by me and my girlfriend, then scanned and recoloured in GIMP. Took a few evenings to prepare them, but I hope they where quite memorable, fun, and did point out the important aspects of what the next topic would be about – an 3 headed dragon as symbol for lots of HEADs in an git repo etc… ;-)

Click to show presentation

I’ve been preparing the flow of all examples before but during the presentation I missed out a few steps and made a some stupid mistakes (see my previous git post on this blog ;-). Well, it wasn’t anything world breaking I guess and I’d really like to thank the audience for such great support. We strayed a little of the path I’ve prepared sometimes, but that’s ok as it was interesting to interact with the audience during an presentation – not just stand there and “praise git to zee heavnz” ;-) Such interaction is something I (personally) really like in presentations, even if they break a little due to this :-)

All in all, we managed to go through all of git’s basic features and in the end even mentioned rebase – which can be used to change the history of ones commits (there’s also the very useful git commit –amend), detached-HEADs and git-svn, which I didn’t use before as I feared a little to make a mess in the company svn-repo (and in all “my” projects I’m using git, so I never felt the need to use git-svn). Some guys sucessfully used it and really recommended it, thus… here I am, doing git svn dcommits on an daily basis… :-) I’m glad to have also learned something from this presentation, not just “showed what I had to show” :-) Now just a few links to very good resources about git:

• A Successful Git Branching Model
• Very good video tutorial on git
• https://git.wiki.kernel.org/index.php/GitFaq
• http://git-plumbing-preso.heroku.com – internals
• https://github.com/ – free opensource project hosting
• and of course: http://git-scm.com/documentation

After the presentation I made an small sms-contest where you could win an PJUG tshirt for guessing what github’s mascot is called like. I hope it was an nice positive accent to finish the session. Next up was the pizza and then 2 more Łukasz’s… :-)

• //TODO: watch on parleys.com
• download slides
• download video

Łukasz Żmudziński – “Project Lombok – Cause We Hate Boilerplate!”

Lombok, if you didn’t see it before is this -> http://projectlombok.org/ It’s a “total hack”, as the author describes it (and he’s right ;-)) but it allows some funny compile time hacks while writing Plain Old Java Code. Łukasz showed us around all the annotations which Lombok provides and how they work, what code exactly would be generated by them etc. The most “let’s you write less code” annotation would be @Data, which at compile time would cause Lombok (…here comes the important part:) to write the source for all setters, getters and toString hashcodes etc – so javac in the end, thinks it’s just compiling plain odl java… Here’s a link on how it works: Data.html The funny part about it is that it’s an compile time tool – much similar to Spring Roo in that aspect if you ask me -  and what it actually modifies is the AST (AbstractSourceTree) that javac then uses to generate it’s bytecode… So no bytecode magic – just how I’d call it… source code injection during compile time? Yeah, weird stuff.

And if you ask me not really something I’d be using all over the place. Sure it’d spare me the writing of some getters and setters and some more tricks but in the end, it’s a problem for not supported IDEs. (How do you explain IDEA that this class really *will have* an setBla() method…?) While NetBeans and Eclipse do have plugins to enable them to unserstand lomboks annotations. It’s not really enough – what about static code analisis tools? They’d go nuts with code that calls methods which dont exist in the source etc :-) Nevertheless if was a fun topic and it definitely is an quite funny javac hack, but if I’d be desperate for such features… I’d go polyglot coding with groovy or scala etc… :-)

• //TODO: watch on parleys.com
• download slides
• download video

Łukasz Czerpak – “Testy jednostkowe i integracyjne w przykładach”

By now you probably noticed it… There where almost only Łukasz’s presenting on this Camp…! :-) Łukasz Czerpak’s topic was about, generally speaking, TDD. He focused (as the title suggests, if you can read polish ;-)) on unit and integration tests. The border between them is sometimes a little blury, but the definitions he have were nice and clear – 1 class = unit, long setup involved = integration. It’s as easy as that, yet sometimes during discussions with other coders these sometimes get confised. Next he went on to some examples of how TDD is useful and finally to a lot of code examples. As he’s using EJBs at his day job, this part was mostly covered – and very interesting (for me, who’d usually just use spring and be done with it).

The mocking framework he used in his examples was of course our Polish Mockito… :-) It’s really great and lot’s of fun to work with, unlike some other mocking frameworks out there. Although easymock would take the 2nd place if I’d were to make an ranking. I’ve also seen a little JMock but it doesn’t “feel good” – but if youre interested in pure “what X can do”, they all do offer the same things, so why bother with some cluttery syntax? :-)

Next, Łukasz showcased using glassfish as an embeded container which definitely is on my “good to know” list and then continued on to an very awesome JBoss library: Arquillian [arquillian homepage] (see? It’s so cool I even had to mark it bold ;-)) It’s an lib which enables you to deploy (yes, “deploy” – perfect word choice) EJBs or even whole archives to an testing enviroment – which would then be started using an embeded container, although as seen on their homepage, they also support remote containers… interesting! Here’s another nice usecase of it: http://ocpsoft.com/seam/cdi-powered-unit-testing-using-arquillian/ The presentation was really well prepared and most probably the high

• //TODO: watch on parleys.com
• //TODO: download slides
• download video

That’s all folks!

We’ll be doing another JavaCamp in the near future (January perhaps…?). But for theese few weeks now we’ll be focusing on the upcomming GeeCON 2011 (Cracow) and kickstarting it’s call for papers (yay, I’m it’s author ;p). And if you’re interested in seeing all recordings on parleys.com and not just as videos – stay on your toes, because after Devoxx we’ll upload them there – I’ll update my blog then and we’ll write an quick news about it on java.pl In the mean time, you can go take a look at these and the previous (javacamp #4) recordings on camp.java.pl – which I just quickly set up to allow you guys quick access to the movies…

Yup, that’s all I think… see you on GeeCON || JavaCamp #6! :-)

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!

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… ;-)

NetBeans.edu.pl

Since Poznań JUG’s NetBeans Platform Training in January (yeah, the one where there was no place left for me ;-)), I’ve been in contact with Poznań JUG‘s Adam Dudczak, Polish JUG‘s Adrian Nowak, Sun’s Geertjan Wielenga and Eppleton’s Anton Epple and many more… And a little later Karol Harezlak joined the training team. We’ve been planing to organize an NetBeans Platform Training in Cracow – since there was really an gigantic response to the training. Now it’s April… and just around two weeks to the NetBeans Platform Certified Training Kraków 2010 ;-) All this could not have been possible if not the great help and support from both JUGs and an amazing amount of help we got from Glider from my University. Also I’d like to give a big thanks to everyone I’ve met during this long process of organizing such an meeting – you’ve all been a great help! :-)

Allright, so what’s this NetBeans Platform all about? To put it simply, it’s “something” (a platform ;-)) that allows you to use all the stuff you see when you do your daily coding in the NetBeans IDE and code up your own application really quickly. While WebFrameworks are really popular and there’s a ton of them, there is not much (worth mentioning) “Desktop App Frameworks” as one might call them. Such apps are then called Rich Client Applications (just a fancy name for “Desktop Apps” ;-)), which makes NBP an Rich Client Platform… You may have heard about “Eclipse RCP” or “SWT” or “Spring RCP” – they’re in the same legue as NBP. But why is NetBeans RCP more interesting than the rest? Well here’s a cupple of reasons I personally find important:

• It’s all swing based, and as Java programmers – we know swing, not necesarrily some “SWT” or “Swing RPC” – right? Less totaly new stuff = better learning curve.
• Your app gets an windowing system abstraction, file system abstraction,  lots of GUI elements out of the box – Tree’s etc
• You can just extend NetBeans IDE or build your own app that looks like an IDE… or doesn’t look like one ;-)
• It’s 100% modular – that means you can use just the stuff you want, or can easily exchange or “lookup” (important word in the NetBeans world) stuff in order to develop apps that can handle plugins and are easily extendible.
• There are quite some inteligent and interesting opinions about NetBeans RCP vs Eclipse RCP on Adam Bien’s blog – (found this blogpost thanks to @timoreilly)

I find the Lexer Api quite interesting but didn’t have the time to really dive into it yet – basically it allows you to write programming language parsing, support into your app or netbeans IDE.
The most amazing… Hmm let’s say “the most visually amazing” app based on the NBP I’ve seen is Gephi (video below). There are lot’s of very complicated apps for biology or airlines and stuff) based on NBP, but let’s face it such apps don’t create an “WOW” effect, unless you totaly understand what’s going on inside of it.

Take a deep breath, and enjoy
NetBeans Platform + Gephi = Graph Awesomeness

Yeah! It’s time for another great JUG meeting. I’ll have to go quite far this time, as it’ll be in Poznań and that’s about 7h by train from Cracow… but at the very moment I saw who was going to be there, that is: Geertjan Wielenga (whose blog I’ve been reading for a long long time and also Romuen Strobl’s pal from the Netbeans team) and Tony Epple, I just knew I can’t miss such a 2-day crash course about NetBeans Platform. I’m mostly interested in EE stuff and didn’t really look all so much into SE apps (just the few while I was very fresh to Java) and this’ll be a great opportunity to see the NBP in action and explained by the pr0s!

It would seem that I’m not the only person who’s excited about this JUG Meeting as during only one day, already 42 out of 45 possible attendands got registered! I already got my Hotel booked and tommorow I’ll buy the train tickets. Oh, and one more great thing  this trip. My girlfriend will some with me so after I code some stuff we’ll check out Poznań – some people told ma that it’s a really nice city. :-)

More information can be found here: (in polish) http://www.jug.poznan.pl/2010/01/bezplatne-szkolenie-netbeans-platform/ or here: http://www.jug.poznan.pl/materialy-ze-spotkan/netbeans-platform-training-2010/ (in english)

—EDIT—

Sadly I wasn’t able to go to this meeting since there were no free places left for students from outside Poznan. I guess thats understandable since they are Poznań JUG, so they want to teach Poznań students more than Cracows students ;-) As sad as that has been for me, something even better came out of it! What? Well, just wait a month or two and I’ll let you know JavaGeeks!