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).

Well, that was all nice and cool but git (other DVCS have this too) has a lot more to offer! :-) Today we’ll look into git bisect and how to automate it’s execution using maven to look for a commit that breakes something. You may run ANY SCRIPT and even write your own and git will use it to test if a commit is “bad” or “good”. Ok, but let’s slowdown a little… What git bisect basically does is performing an binary search, between a range of commits you specify looking for “the first bad commit” you you can easily find what caused the bug and fix it. You can drive it by hand and after starting git bisect just test the commit by hand and tell git if it’s good or bad by “git bisect bad” “git bisect good”. Git is smart enough to find what commit he should “git checkout …” next to perform a binary search based on your anwsers.

Today we’ll learn how to make git cooperate with maven and find the first commit that introduced a test failure. See bellow for the full workflow you showcasing this:

Ok up until now we’ve just created a simple repository we’ll be running the tests on. Let’s tag this state as “yeah it’s working here” just so that I don’t have to remeber the SHA-1 of this commit.

And now we’ll run a script that does some random commit action, just so that bisect has a lot of commits to work on.

The tests are still passing… time to change that! We’ll break the build with the following commit. And then generate yet another 50 commits to “hide it”… ;-)

Ok the test’s fail now. But suppose you didn’t know which commit introduced the bug (in our case made the test’s fail). You’d have to guess which one, or check them all or just work it out by looking at your current repository state. But since you’re doing small commits and do them often – it’ll be great if you found out which commit caused this failure. As it’s preferably small, it’ll be very easy to find out what change caused the build to fail. No is the time to use git bisect!

We’ve started bisect, and told him which commit we’re sure is working and which we’re sure is failing. Git will now checkout a commit he found “somewhat in the middle” and will continue to bisect (binary search) the commit history based on wether a commit is “good” or “bad”. We could just tell it git by hand by doing “git bisect good/bad” etc. But let’s git bisect run a script to do this for us :

Yeah, we’ve found our failing commit :-) You could use any script you want here, it just has to return 0 if git should think it’s a “good commit” and “not 0″ if it’s a “bad commit”. I’ve even seen runners written in PHP running or spellcheckers – you name it… :-) Ok but how does this magical script that we’ve just run look like?

Whoa, that’s simple… :-) Keep on git hacking guys! See you soon, with some more git or java tips… :-) Oh and I’ll post my presentation (holefully with video) from SFI soon, so keep an eye out! :-)

PS: Yup, the code retreat we’re (SCKRK with a little help from the PolishJUG) organizing got “sold out” after just 3h… ;-) Be sure to take a look and be quicker next time! http://coderetreat.sckrk.com

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 :-)

So… Since I’ve started using git-svn at work, I do have an possibility to make things better now! The answer lies in client-side-hooks and git aliases (“custom commands”). First let’s write this as an simple bash script, that we’ll locate in the .git/hooks/ folder:
It’s a fairly simple script, so I wont bore you explaining it in detail – if in doubt, feel free to ask. We only need to place this script as “.git/hooks/pre-commit” and make it executable and git will take care of the rest for us. Oh and in case you’re wondering where that org.eclipse.jdt.core.prefs came from. It’s created by eclipse into the .settings folder when you check some option to “use formatter per project” – that’s the only time I had to fire up and click around in eclipse to get it’s formatter running “headless”. Ok, let’s check if it works…

Yup, you can agree or not with the formatting rules – but what matters is that the whole team decided on it and that we keep it consistent throughout the whole project. This hook will definitely help with this. :-) Step two for me was changing this into a git command, so that I wouldn’t launch eclipse each time I just do some quick local commiting. The solution is to drop the hook idea (although it’s quite nice) and create an custom git command. We do this by doing an alias like that:

git config --global alias.eclipse-formatter '!~/git-hook-eclipse-formatter'

The !command alias support is with us in git since 1.5.0 and it enables us to launch any program/script as an git command. Great, just what I wanted! Let’s now see what this command really did:

As you can see, adding an alias is as simple as adding it to your ~/.gitconfig or, if you want to setup the alias “per project”, to .git/config – pretty cool, ay? Also, this command will be included in bash-autocompletition suggestions! :-)

That’s it for today… happy hacking!

If you code in Java, you most probably use (you really should use) some dependecy injection mechanisms. They’re really great and take care about all the setup that need’s to be done before you can move on to your coding. The same thigh applies to testing, you’d rather write:

Than use the new operator, or worse, perform some super weird setup to build this object. If you use spring, you’d write an test like this to make it support Spring’s DI:

That’s all you need to make your tests properly autowire all components they’re using. So far so good – probably nothing new here, and nothing complicated. So let’s move on to some “super big data set” that needs to be tested, over the same flow over and over again. We’ll use an super conplicated example to showcase what I mean:

Ok, that’s obviously stupid… :-) So, how do we deal with repetitive tests, that need some bigger dataset than just this email example (given here because it’s short and good enough for our example test)…? We’d use @RunWith(Parameterized.class), the class would then look something like this:

Ok, that’s a nice way to make your code in the tests smaller yet have an nice overview through all of your tested data. Each array will be inserted in the constructor, and then ran as an seperate test – with each dataset. Nice, isn’t it?

Ok, but what if we want to have both Spring’s DI and an @Parameters “test data provider”…? Can you spot the problem? Yup, JUnit4 can only have ONE @RunWith annotation, and it doesn’t accept multiple runners. Which totaly makes sense when you think about it, but then there is our special case of DI, which really doesn’t change the way an test wotks, it just makes setup easier… All that said, here’s how to use both spring and parameters in your Junit4 tests:

That’s it :-) We do what the spring Runner would do for us, instanciate an application context and prepare it – that’s when the DI happens. Note that we cant use another runner annotation, but we can as usual specify where to find the appContext.xml’s.

That’s all, hope this will prove useful to some of you :-) Keep your tests clean!

PS: Warning, most of this code was written in wordpress, it may contain minor spelling errors ;-)

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 my blog is being listed on http://www.dworld.pl/Blogsfera (and for other obvious reasons) I didn’t want all my tweets to be translated “1 to 1″ to plain old blog posts since this would cause each of my tweets (which can be silly sometimes (but quite rarely!)) to land on dworld, which they obviously shouldn’t as it’s only an place for Java/Development oriented posts. Also I’d rather they’d take less space, and would skip all the categories/tags – it’s all in the tweet, so why repeat it again and again?

So… let’s start by importing tweets into wordpress. There’s an great plugin for that, and it’s called Tweet Import by skinju. Just install it and set it up to fetch your tweet’s at an regular basis. Ok, we’re done with step 1 – but neither are the current tweets smaller or ommitted in the rss feed. Let’s start by filtering them out from the rss feed:

Open up the file /wp-content/themes/default/functions.php and go to the end of the file, we’ll add an filter here. Please note that in step 1 you should have created an “twitter” category all tweets should be marked with. Let’s assume this category has an ID of 131, then the following code would do the filtering for us:

It’s a very nice trick, and it’s explained more in detail here. The code is really simple, so no explaining here and let’s go and tune our view (yup, the RSS feed is already fixed!).

To setup our view to work a little different for tweets than for posts, well have to edit: /wp-content/themes/maze/index.php so open it up in your favourite editor and add such an if statement inside an post’s while statement:

Ok, with this done let’s write the else part…

(You can complain about the in line css styling if you want later, I know it’s bad but this wordpress theme is a mess anyways… ;-)) Let’s have a look at the more important parts of this code part. You’ll notice that I’m using some weird get_post_meta() function. It’s an method that fetches additional information that each post CAN but doesn’t have to have. And as the TweetImport plugin does fill an post with a lot of useful tweet data, such as post time and tweet url – that’s what I’m fetching here. The rest should be quite self explanatory, there are bit’s of hardcoded “ktosopl” in there but hey – it’s just my blog and I’m a busy person ;-)

Hope you found this post interesting and maybe you’ll implement the same thing on your blogs…? :-)
Cheers!

PS: Oh, and if your interested in talking on one of your upcomming JavaCamps – feel free to contact me or anyone from the java.pl team, we’re looking forward to hearing from you. The nearest meeting will probably be organized around 23′th or 6′th…

Yup, that’s basically it. You may also apply this directly in vim as I’ve showed here a few years ago and you’ll probably need to look some stuff up here or on this awesome sed guide.

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~

As I’ve been recently given a task to “copy & paste” all our properties into an specific document on google docs – that the client wanted to use in order to translate these properties into other languages. Of course I decided NOT to do this by hand – but script it – and that’s how props2xls came to be.

It’s an Groovy + Java app that traverses an directory searching for *.properties files, and then matches their names together – and extracts their Locale from the filenames. Next, those strings are uploaded into an specified Google Spreadsheet. You can use any google account + password anc choose which spreadsheet/worksheet should be filled out with your data.

Note that the bottleneck here is the inserting into the Spreadsheet. This can be easily and very much improved as one may use Batch inserts. But as it’s just a proof-of-contept, I didn’t actually care for the time being ;-)

Here are some useful links if this post got you interested in this API:

• http://code.google.com/p/gdata-java-client/
• http://code.google.com/apis/gdata/articles/java_client_lib.html#linux

As all programmers… you’d also probably want to check out the source – so here (on github) it is. But be warned, it’s very low quality as it’s just been hacked on for a few hours today at night (after midnight… ;-)).

—- the UPDATE —-

As you’ve probably noticed. In the first version I was using cell-by-cell updated. Each of them would fire an HttpRequest… And that is very expensive. So… I’ve rewritten some of the code to enable Batch updates. Goodle APIs support is quite well and I’m happy with the end result (as seen in the above movie).

There is a bug in the Java Client Library from 2.0 up though… When creating the SpreadsheetService use the following code, or you’ll run into some weird bugs at runtime:

PS: One might call it an proof-of-concent, as the code is quite ugly but it was written in about 3-4hours. And will probably spare us a lot of time if some client wants to translate our properties once again… ;-)

PPS: Did you know that on the netbeans.edu.pl website, I used the Google Data API for Picasa to develop the gallery?