Adventures in a changing world

Upgrading to Ubuntu 11.10 with Oracle 11 XE

2011-11-04T06:57:00.004+01:00

Well it's been **very** busy times since the last time I've posted something here. Anyways, I've installed Oracle XE 11 pretty much the day it came out (4/sep/2011) and I've been pretty happy with it since then. Since it was running on ubuntu 11.04 and Ubuntu released a newer version (11.10), I thought let's upgrade since it's pretty much a no brainer with ubuntu (do-release-upgrade and you're good to go). But then things went south...

When restaring the VM oracle didn't seem to be there. Yes the listener was there, but that was about it. Where did the database go?

hmm let's see

Connecting on the machine itself with an sql*plus

ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0

Ok, maybe it just didn't autostart for some reason.

> su -l oracle

> sqlplus / as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Thu Nov 3 21:42:28 2011

Copyright (c) 1982, 2011, Oracle. All rights reserved.

Connected to an idle instance.

SQL> startup
ORA-00845: MEMORY_TARGET not supported on this system

heh?

Memory_target is the new (well since oracle 11) in any case to handle it's memory. instead of defining your PGA and SGA separately you just tell oracle that it can use so much memory and it'll try to determine for itself what the correct ratio for your instance should be. Except now...

Apparently one of the big changes for ubuntu 11.10 was that they've moved away from the /var/run, /var/lock and /dev/shm which oracle used for determining how much shared memory you had. So now you've got 0 bytes of (shared) memory as far as oracle is concerned...

Currently there are 2 workarounds for it:
* modify the binary oracle executable (I'd rather not, thank you)
* tell oracle what ratio to use instead of letting it figure it out for itself.

So latter approach seemed fit.

Ok here we go:

> sqlplus / as sysdba
> create pfile='koen.ini' from spfile;

File created.

vi ./product/11.2.0/xe/dbs/koen.ini

remove the memory_target entry and replace it by

pga_aggregate_target=200540160
sga_target=601620480

> sqlplus / as sysdba
> startup pfile=/u01/app/oracle/product/11.2.0/xe/dbs/koen.ini

ORACLE instance started.

Total System Global Area 601272320 bytes
Fixed Size 2228848 bytes
Variable Size 180358544 bytes
Database Buffers 415236096 bytes
Redo Buffers 3448832 bytes
Database mounted.
Database opened.

Et voila..

Hope this helps someone having the same issue..

Now we're talking...

2010-01-24T21:21:00.002+01:00

Tomcat 6.0.20 finally supports proxied getRemoteAdr()

2010-01-05T21:31:00.002+01:00

I've encountered this bug recently as I wanted to find relate sessions with their originator on a load-balanced tomcat in front of an nginx acting as a proxy. Until now I always had to put this in the lib folder of a tomcat installation. Now the guys from apache finally integrated it into their codebase (6.0.20) and it works right out of the box. Whoohoo!!

Happy new year !!

2010-01-05T16:38:00.000+01:00

We've got a little girl!!!

2009-09-06T16:21:00.002+02:00

Elise was born last Tuesday, 1 September.

Cometd vs BlazeDS : pushing messages to the client

2009-08-04T00:34:00.005+02:00

In the constant quest of allowing web applications to use more functionality that was once found in fat clients (eg. VB, Delphi, C/C++). It has been historically difficult to push messages from the server to the client. Not only were there hoops to jump through on the network level, almost all (stateful) firewalls only allow sending data to a client that already established a connection (the famous syn bit). There is also the problem that most http servers (IIS and apache) don't like too many connections open for too long as they typically allocate memory to a connection. Furthermore on the client side, browsers didn't (until recently) have a standard way to handle server side events. And if things weren't bad enough there is still the minor issue with browser incompatibilities with IE as the negative role-model.

There are however a few alternatives to circumvent these limitations on which I'll highlight 2 (that I've used from personal experience).

The use case for this was in a domotics program (a pet project I work on). Here a java backend was connected via the serial port to the domotics bus. As soon as an event (being for example a light switched on) I wanted the status of the light updated in the front end. So the front-end contained a image representing the living room and smaller images the states of electric bulbs in that room. If one switched on the light then the same state would be represented on screen as soon as the event occurred with the least possible latency.

* Option 1 : Flex front-end and BlazeDS/GraniteDS backend through JMS

Although a Flex application on the front-end feels a bit like cheating, since the true source code is a bunch of actionscript files compiled into a SWF (aka flash file). It still gives the user a natural user experience in the browser. This flash file connects to the backend via amf over http. The AMF protocol is a proprietary binary protocol opened up recently by Adobe, which allows flash clients to connect to a backend. Until recently their backend of choice was either coldfusion or jrun, but since other web application servers (and tomcat/jetty in particular) were so widely used, Adobe open source'd BlazeDS as well. This combination has an option to use through JMS push server messages to the client.
BlazeDS and Flex were pretty simple to setup, but on the backend side, one required JMS which was typically not included for tomcat/jetty or one should switch over to a full blown J2EE server in which JMS was supported. Certainly with the new Web Profile of the the J(2)EE version the question pops up again which JMS system to use. Here again, tastes may differ, but I have a small tendency towards ActiveMQ as it's really fast and provides all kind of features like streaming messages.
Towards BlazeDs, there is however an alternative called graniteds which I favor as it contains less dependencies (like concurrent.jar, which is the predecessor of a backport of java.util.concurrent, old in other words) Their implementation is based on option 2 and is an implementation of the Bayeux spec as well.

* Option 2 : Html/javascript front-end and cometd backend

For me this was new (well I had heard about it, but I never came to test/use it). So there I was on (another) late nighter trying to find out more about HTML5 which seems to be a hot topic these days with stuff like the event sources and client-side caches. Problem was that there isn't that much material about the subject since the final spec is about to be released in 2022. So looking at event-sources it made me think back about cometd and I decided to give it a spin doing just a simple use-case like visualising the amount of free memory on the server. Although it didn't have any real immediate benifit, it was easy enough both backend and frontend to get me started to find out if it did fit my use-case
Boy, was I in for a surprise...

First of all, as with html documentation is a little scarse, although better than HTML5. The things I found however were still usable enough to mash up something useable together. So first step, backend (for me usually the easiest). Instead of starting my use case I decided to first try it with the proverbial hello world, to eventually step it up to my use case.

1. Import the required dependencies to use Cometd (or it's Bayeux implementation). These are small "cometd-java-server" is all you need to look for in the maven repository.
2. Implement a listener
3. Start sending messages out (by using the 'publish' method) As a merely sample project I outputted the memory available, the eventual use case would consume events from the serial port.

One note, I needed to import "org.eclipse.jetty.util.ajax.JSON.Literal" as it otherwise seems to escape quotes in the publish of a JSON message which renders the solution a bit less optimal :(.

On the front end, things couln't be simpler either.
1. Reference the cometd and it's implementation script (I chose to use jquery)

    <script type="text/javascript" src="${pageContext.request.contextPath}/org/cometd.js"></script>
    <script type="text/javascript" src="${pageContext.request.contextPath}/jquery/jquery.cometd.js"></script>

2. Upon handshake, add a listener to the meta channel to listen to the channel on which you publish messages

         cometd.addListener('/meta/handshake', this, function(){
                cometd.subscribe('/monitor/jvm', receive);
                                 // Allow content to show
                $('#mem').show();
        });

That's it, now you'll have updates on memory usage on the front-end. I added a small visualisation library to the mix so I could come to the following :

Great presentation on oracle databases

2008-10-22T21:01:00.004+02:00

This is a must read for everyone who does anything with oracle databases.
More often than not you find yourself in projects where developers see the database as their enemy. People who know me, know what I'm talking about ;)

Oracle Database Worst Practices - Upload a Document to Scribd

OpenID

2008-07-04T13:13:00.004+02:00

You certainly know the problem: you have literally hundreds of websites asking you to invent a username and a password, which you'll have to remember potentially weeks or even months later. Well there's a solution:

OpenId works as follows :
1. You log into a website with your openid "URL" : Mine for example is http://kserry.blogspot.com/
2. de webpage you want to login to is redirecting you to your provider.
3. on the providers' website you login with your credentials (this is the only you'll have to remember)
4. the providers' website redirects to back to your original website and you'll either be presented with a form (without the fields you allowed your openid provider to see to external parties and without the username/password)

How this works [Technical]

Migrated pebble to blogger

2008-07-02T21:15:00.004+02:00

Thanks to the guys from google we got a API to post items to our blog. Since I've had a pebble blog for some time now, but I don't have access to that server anymore, the time had come to use something with less maintenance (read none).

Hereunder you can find the code I've used to migrate the entries. Note: There are 2 steps 1. use an xslt to transform the pebble xml to an 'atom' xml. 2. use the python script to upload The xslt




<xsl:stylesheet version = '1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>



<xsl:template match="/blogs">

<xsl:for-each select="blogEntry">

<entry xmlns='http://www.w3.org/2005/Atom'>

<published><xsl:value-of select="date"/></published>

<updated><xsl:value-of select="date"/></updated>

<category scheme="http://schemas.google.com/g/2005#kind" term="http://schemas.google.com/blogger/2008/kind#post"/>

<title type='text'><xsl:value-of select="title"/></title>

<content type="html"><xsl:value-of select="body"/></content>

<author>

<name>Koen Serry</name>

<uri>http://www.blogger.com/profile/03836830737950982447</uri>

<email>koen.serry@gmail.com</email>

</author>

</entry>

</xsl:for-each>

</xsl:template>

</xsl:stylesheet>

Here is the python script.


import httplib,urllib,re

from string import Template



params = urllib.urlencode({'Email': '', 'Passwd': '', 'service': 'blogger', 'source': 'exampleCo-exampleApp-1.0'})

headers = {"Content-type": "application/x-www-form-urlencoded"}

conn = httplib.HTTPSConnection("www.google.com")

conn.request("POST","/accounts/ClientLogin",params,headers)

response = conn.getresponse()

print response.status

data = response.read()

conn.close()

print data



auth = re.search('Auth=(.*)$',data).group(0)

print auth





s = Template("""



$header

$payload



Koen Serry

http://www.blogger.com/profile/03836830737950982447

noreply@blogger.com



""")





f = open("blog.txt")

title = f.readline().rstrip()

content = " ".join(f.readlines())

params = s.substitute(header=title,payload=content)

headers = {"Authorization": "GoogleLogin auth="+auth,'Content-Type': 'application/atom+xml'}



conn = httplib.HTTPConnection("www.blogger.com")

conn.request("POST","/feeds//posts/default",params,headers)



response = conn.getresponse()

print response.status

data = response.read()

conn.close()

print data

Rhodos

2008-06-30T07:12:00.002+02:00

Ahh, well earned holiday on Rhodos. As you can see my son grew up quite a bit and is able to walk already.

Maven2 just got 2 great improvements

2008-02-12T21:13:00.001+01:00

Maven2 recently got 2 big improvements.

mvn archetype:create

allows you to create a new project from scratch and start with an existing project infrastructure that you can easily adapt. Previously you had to pass options in via the infamous -D parameter, now it guides you through some kind of wizard.

The other enhancement I just read on Brett Porters website where you will in a future release be able to condense your xml in the pom to attributes (more info here)
Finally you'll be able to see all your dependencies without having to scroll for ages :)

Even quieter than before.

2008-02-09T20:38:00.001+01:00

The project I'm currently doing in my day-job went live this week. So plenty of work (as well as hours), but fortunately the dust is finally settling down.

Just got dad :)

2007-04-24T17:07:00.001+02:00

Been pretty quiet last couple of months, here is the reason. Proud as a new father I present you my son Nathan born on 19th of april.

Second step into real electronics

2007-01-12T20:10:00.000+01:00

Ok seems that my ICD2 was faulty. I can't wait untill it gets replaced.

First steps into real electronics

2007-01-05T22:47:00.000+01:00

Ok, we've had electronics classes when I was studying. But nothing like when you're messing around with it yourself. So this year my promise was to get into the electronics/microprocessing thing. I bought a PICDEM2+ board to try things out. And today they arrived YAHOO....

The Board is working, the ICD2 is working, now why can't they see one another. read 0x0 what is this?

Year in pictures [DUTCH]

2006-12-31T13:50:00.000+01:00

Hilarious

Tech Support

2006-12-23T16:29:00.000+01:00

Hilarious cartoon

OpenID & Windows CardSpace

2006-12-21T06:29:00.000+01:00

Long time since I've blogged. Just had a look at Windows Cardspace, looks promising but apparently there's
a similar service vendor independant. I've just enabled
mine its at http://koen.serry.myopenid.com

IE is just crap

2006-08-16T01:29:00.000+02:00

As happy as I was that I was using AJAX in my latest webapp (http://www.proco.be) as disappointed I was that
the prototype library (Ajax.Update in particular) didn't seem to work on larger datasets in IE since its
header has a certain limit. As usual IE just swallows the error.

Since webwork is
using dojo internally I was given a choice but I found prototype easier to use, so now I was forced using
dojo. OK modifying, debugging couple of hours later...
system error -1072896748 in IE's
usual javascript error box
WTF??
Googling a bit pointed me to some weird
error in the MSXML parser that couldn't handle UTF-8 (mind the dash). OK fixed, another error in IE, what's
next...

Well got an even nicer one.. Seems if you take an element and give it
id="description" and try setting the innerHtml of it it won't work. Setting it to whatever magically fixes
the stuff.

Why is following the standards so hard?

First post on the new blog

2006-08-15T06:29:00.000+02:00

Fjew,finally done. Just installed the new server and I have to say it, it's a lean mean killing machine :)

The webapp is completely build via webwork 2 and I have to say it, it really rocks. Validation, I18n and
that combined with the radeox engine (which needed some modifications that I'll need to post back to the
authors still)

OK, more on this later.

.Net collections and the need for speed...

2006-03-23T17:29:00.000+01:00

<quote>
A few comments from 'The Other Side'

I've been
reading your blog since I'm doing occasionally stuff in .net, but java is where my heart is. But this entry
gave me the creeps so I couldn't resist commenting on this blog entry of href="http://community.bartdesmet.net/blogs/bart/archive/2006/03/22/3831.aspx">Bart
Desmet.

If you're using JDK5 (and it seems you did) you may have noticed
that new ArrayList().add(1) actually works. So boxing and unboxing has made it into Java too (Although I'm
not sure this is a good thing).
Second the collections framework in java is imho far better than
.net, first of all there is no common interface for (non-)generic collections in .Net. So
System.Collection.Arraylist doesn't implement System.Collection.Collection or whatever, like they do in
java. This would actually allow components to be written that take collections as an interface, regardless
of how they're implemented. Or to have open source alternatives, that could turn out to be
faster/lighter.
On the backwards compatibility, while it's true SUN could have opted for putting
them in a seperate package, they didn't. And quite frankly It doesn't even bother me that the compiler warns
me about it, since I can either disable them or use generics. What this has to do with versioning hell is a
big question mark for me. Java hasn't suffered from versioning hell like .net does. We do however have our
own issues like ClassNotFoundExceptions, ClassLoaders and stuff.
Although things have improved
since the 'COM' days, I don't know about something like class loaders in .net that allows usage of separate
versions of the same package in the same program. And then we didn't discuss about the backwards
compatibility between .Net2.0 and 1.(0|1) which is if you ask me questionable.
As far as startup
time is concerned, well the statement that .net is 2,2 times faster than java based on a simple program like
that, where the JVM has the disadvantage of not being partially loaded into memory already, I'll leave that
to you.
</quote>

Quest for more competition

2006-02-27T18:29:00.000+01:00

or how the quest for more competition of the European Commission can have the opposite effect. />

Since more competition usually means lower prices for customers, everyone was in favour of
these rulings.
Now, lower prices means also lower margins, it also means that if companies want
to maintain their level of profits
it would require cost-cuttings as well. Now unfortunately most
effective cost-cuttings are done where the costs are highest.
Till this day this is still labour,
the way companies are doing this is either fire people or do major mergers. So instead of 2 persons />in 1(2) companies doing the same job, ending in only 1 person doing this job. If you see this on a
european scale, this in effect lowers
the wages as well. So now, is more competition better for
the european population or for it's companies in the long run? Strange how good measures can have a twist
and why the gouvernment should thing twice before adding additional legislation.

Re: Usability problems in JSF

2006-02-23T18:29:00.000+01:00

A while back I've posted a compairison on
JSF vs Tapestry and even though it was a while back (last year). The points are still valid. If
you have something to add, see href="http://sfjsf.blogspot.com/2006/02/usability-problems-in-jsf.html">here another person
with some issues with JSF

Geronimo & Deployment Descriptors

2006-02-09T22:29:00.000+01:00

I'd already checked out Geronimo before when it was still in Milestone stage, but since it got released I
finally got myself to actually deploy a complete earfile in it (so including an EJB module (Session,CMP and
messagedriven beans). Well I can say it's not as easy as it looks. Ok, they have a hot-deployment directory
and a nice "console" web interface, but that's where you can stop the comparison.
/>What I **don't** like at all is the excess of deployment descriptors. Just when everybody agrees that
there are too much DD around, just to deploy a simple war file in geronimo you need something called a
'deployment plan'. This is ok if you want something special for a particular kind of configuration. But what
if you'd settle with the defaults...Even SUN won't make that mistake twice.

New member of the family - Dina

2006-02-07T22:29:00.002+01:00

Last saturday we got our new puppy (a jack russel).
On this picture it's really quiet and peaceful, but that's since she's asleep.
Otherwise she's a whole lot more active.

JavaPolis: First day of Conference (3/5)

2005-12-26T13:15:00.000+01:00

Third day at Javapolis was kind of strange if you ask me.
The keynotes were nothing extraordinary and then we were already halfway the day...

So at 11.30 I went to What's new in NG Mobile Java as this is a bigger market than J2SE/J2EE will ever be. Even though job demand isn't that big here in Belgium for these kind of jobs. Beside the updates to the CDC / MIDP API's one thing caught my attention. JSR-180 which allows you to connect to an SIP proxy from your mobile device. This could turn out interesting, as soon as your mobile can connect to either to a WLAN or via bluetooth to the internet, it could connect to your SIP proxy avoiding the usage of the mobile network (and reducing those pesky bills :) )

Next talk was unanimous: EJB3 by Linda DeMichiel and Mike Keith, the romm was filled to the brim. Although I didn't hear a lot of new things I was still exited about how SUN finally did the right thing (even though they are screwing up JSF). So after lunch most of the crowd still exited about EJB3 wend to Seam. That seems to integrate EJB3 and JSF. Oh my... even though expectations were set at the beginning of the presentation regarding 'fix for back button' and '2 windows to the same webapp' the end of the presentation was undermined <<completely>> by the lack of knowledge of either the English language or Http Sessions. I hope it was the first. When people asked how they'd fixed the "2 open windows" problem Thomas answered 'we handle it on the server side, with cookies'. Well, sorry, at that time I wasn't the only one leaving the presentation.

One thing I was really looking forward too was the presentations by Brian Goetz about Concurrency Utilities and the Memory Model in JDK1.5.
Among others he talked about :

Executors: objects that define how, when and how many concurrent Runnable tasks will be executed. Even though one may think this is trivial, it's nice that SUN made a couple of default implementations like ScheduledThreadPoolExecutor and ThreadPoolExecutor.

ConcurrentHashMap which allows concurrent access to a Map without throwing the notorious ConcurrentModificationException as it doesn't block concurrent access, but does impose some restrictions on modifications in terms of concurrent threads

Condition / Lock in order to keep your code somehow cleaner than with the wait/notify. Like this rip from the javadoc clearly shows,


 class BoundedBuffer {
   final Lock lock = new ReentrantLock();
   final Condition notFull  = lock.newCondition(); 
   final Condition notEmpty = lock.newCondition(); 

   final Object[] items = new Object[100];
   int putptr, takeptr, count;

   public void put(Object x) throws InterruptedException {
     lock.lock();
     try {
       while (count == items.length) 
         notFull.await();
       items[putptr] = x; 
       if (++putptr == items.length) putptr = 0;
       ++count;
       notEmpty.signal();
     } finally {
       lock.unlock();
     }
   }

   public Object take() throws InterruptedException {
     lock.lock();
     try {
       while (count == 0) 
         notEmpty.await();
       Object x = items[takeptr]; 
       if (++takeptr == items.length) takeptr = 0;
       --count;
       notFull.signal();
       return x;
     } finally {
       lock.unlock();
     }
   } 
 }

About the talk of the Java Memory Model I remembered that one have to be extremely careful with assuming stuff in java. The compiler can do stuff you didn't think of initially
For example who would think that


while(!asleep)
   sheep++;

could turn by the compiler into something like

if(!asleep)
   while(true)
      sheep++;

Keeps me up at night :)

Javapolis Day 2 - Spring 2.0 & Agile Development

2005-12-24T16:07:00.000+01:00

Title says it all

Spring Business tier gave me quite a surprise as finally we can create those dreaded XML files by the use of schema's so validation won't have to be done at runtime anymore. Also something like custom tags will be in the next version of spring allowing some commonly classes to be used without the FQ package name. Among others, tags for properties and transactions.Can't wait to get my hands on this release...

The afternoon I didn't know what to choose at first. OK Spring Web and Ajax were kinda appealing, but since it was more of the same, I decided to listen to Scott W. Ambler on Agile Model Driven Development. Not with much hope as at that time I didn't know he was such a big shot. He did mention some pain points in development. Like traditional development cycles taking too long and losing touch with customer and requirements. Or how to handle burocratic managers requiring an overload of documentation.

He also made the case against requirements up front. As most customers will then try to come up with as much requirements as they can think of at the time loosing touch with the actual requirements. Hence applications can be made were two thirds of the functionalities aren't used at all, causing these projects to go over-time and budget. We should therefor allow our customers to change their minds.

However, most of the customers expect projects to go over-time and budget, so they endorse fixed-price projects. This forces us then back to the old style where we need the requirements back up front since otherwise we can't make our estimates about the application. sigh...

Old Year's Photos

2005-12-23T12:56:00.001+01:00

Reuters Year in Photos

MSNBC

Thunderstorm

Israel: Settler pleads to stay in Gaza

War in Iraq: Honoring a fallen father

Javapolis 1/5

2005-12-23T09:21:00.000+01:00

OK I admit, probably way late to write something about Javapolis which I attended last week. But well, since then I had so much new things to discover that I decided that it's better to be burried under work than to appear alive :).
I'll split this up in seperate days so you don't have to read it as one big chunk.

But first a picture...

If you're looking for me (for some strange and obscene reason) I'm way off to the right and probably fell of the picture.

Ok first day, since it was university one 2 speakers a day, which made it kinda interesting as when you made your pick it was for half a day. My choices the first day were Apache MyFaces and Using the EJB 3.0 Reference Implementation. Although I have to admit that I was tempted to go to Desktop Java In Action by Romain Guy from Sun Microsystems. But since I'm a frequent reader of his blog, I thought go for something you know less about.

MyFaces by Jonas Jacobi,Martin Marinschek and John Fallows: I've been using JSF to do the SCEA assignment last year and I found it a bit limited and full of quircks. But since a year has passed and things tend to change I wanted to see how things hopefully improved. Event though I didn't see any actual improvements (but more on that later), the announcement & demo (and actually rest of the talk) was made by Oracle that was going to open source it's ADF component suite.
I've been looking to this and found it quite impressive but I've avoided it like the plague since I didn't want to be locked in. But now...
This announcement was made in the MyFaces talk because of its future name MyFaces Cherokee although I haven't been able to find it on the incubator site of apache, it should be there next year (2006).

Using the EJB3.0 RI seemed to appeal to me as Sun finally understood that developers don't just take anything (like the M$ guys from technet sometimes seems to think) although when you look at JSF...
Anyway, when you look at EJB3 the JSR members really seem to have done their homework. Finally no more blunted XML files (that everyone created through XDoclet anyway), simple POJO's, even the cmp's. Ahhh, what a relief to see that the most common options are now defaulted in the annotations (yes, java5 is required). Anyway the talk was really good filled with lot's of examples. Mike Keith really explained the persistence part very well. Things like the difference between EntityManagers and persistence contexts and how you can do queries now in EJB3. (Dynamic and static ones). As soon as can get my hands on this one, more of this

Combining the best of breed

2005-11-02T23:28:00.000+01:00

Nice tutorial on how to integrate Lucene with spring and hibernate.

Flock

2005-11-02T20:33:00.000+01:00

Just encountered a firefox fork that enhances the browsing experience even more that firefox does. (Didn't think this was possible) It easily integrates Flickr and Deli.cio.us. Great just what I've been looking for.

Python assimilated

2005-10-14T09:24:00.000+02:00

Just as I was getting into python, I've hear that Microsoft is releasing IronPython as well.
This may not have come as a surprise since Microsoft had hired the guy who started Python, but history repeats itself!

Great laugh for developers

2005-10-05T13:41:00.000+02:00

How NOT to do things.

http://mindprod.com/unmain.html

Added traffic situation for going home

2005-10-05T13:20:00.000+02:00

As may have noted, on the side you now have an image indicating how the traffic is like going to Brussels (where I work). I knew the site verkeerscentrum.be contains a nice overview of what's going on + certain images of the traffic on certain places. I just found out the URL to these images. Here they are... drop me an email how you use them.

E-17 Zwijndrecht, direction Antwerpen

Ring Antwerpen West, direction Antwerpen

Ring Antwerpen Kennedytunnel, direction Gent

Ring Antwerpen Zuid, direction Nederland

Ring Antwerpen Oost, direction Nederland

Ring Antwerpen Oost, direction Ranst'

Ring Antwerpen Merksem, direction Gent

E19 Antwerpen Noord, direction Antwerpen

E313 Ranst, direction Hasselt

E19 UZA, direction Antwerpen

E17 parking Kruibeke, direction Gent

E40 Ternat, direction Brussel

A12 Meise, direction Brussel

E19 Machelen, direction Antwerpen

E40 St-Stevens-Woluwe, direction Brussel

E411 Overijse, direction Namen

QRCode

2005-09-21T10:45:00.000+02:00

Finally something really innovative in the world of cellphones. Like an FM-tuner or an mp3 player, a digital camera on a cellphone didn't make sense to me besides the generation of traffic for youngsters. That was until now. If combined with something called QRCode which is a 2D barcode easely recognised by software (don't know yet how easy) it could allow people to have an easy lookup information on the net.

The people at semapedia.org allow people to generate such a QRCode with the url to whatever (they take wikipedia, but it's non specific) that they can print out and put it onto/next to an item. This way if you encounter something which you don't know what it is (but like to find out), just scan it with your cellphone and see what page it brings you.

I'm pretty sure those spam-criminals will find some use in this pretty soon...

Wicket vs. Tapestry4

2005-08-26T17:01:00.000+02:00

Last couple of days I've been tossed between Tapestry 4b3 and Wicket 1.1b3. Both of which integration with Spring is quite problematic.

Things I like about Tapestry(4):

Full control over pages/components

Once Spring is integrated, full IOC is possible.

Nice components available (eg. Tacos)

Things I don't like about Tapestry:

Quite a lot of dependencies (Here less is beter)

Hivemind.. (way to beta to do some actual work). Try integrating it with hibernate for example..

Directory structure. HTML pages fload around in the classpath without the possibility to have them

But comparing them with Wicket...

Good things:

Strong typed

Real components (class+html) possible (just drag a jar in the lib folder)

Good I18n possibilities

Good templating possibilities (both HTML and class)

very few dependencies

Spring can be integrated by encapsulating it in the Application class

Things I don't like about Wicket

Everything needs to be defined in java, no pull possible

Getting the HTML right is hell, tags aren't replaced they are filled

Components require the right tags

No real IOC

Israeli technology

2005-08-05T10:12:00.000+02:00

I just found a whole lot of interesting new technology articles on the Isracast site. Really quite interesting. Some samples:

PEN-LIKE INSTRUMENT WILL SNIFF OUT EXPLOSIVES

ISRAELI COMPANY DRIVES THE LARGEST SOLAR PLANT IN THE WORLD

LIKE A FISH - REVOLUTIONARY UNDERWATER BREATHING SYSTEM

CELL PHONE RADIATION MAY CAUSE VISUAL DAMAGE

Boycott IE7

2005-08-03T10:33:00.000+02:00

Paul Thurrott, a journalist that usually writes about all things windows related (and sometimes about Apple affairs too), made a call in a recent article to boycott Internet Explorer, due to Microsoft's approach (continued in IE7) of not supporting web standards

It's a cancer on the Web that must be stopped. IE isn't secure and isn't standards-compliant, which makes it unworkable both for end users and Web content creators. Because of their user bases, however, Web developers are hamstrung into developing for IE at the expense of established standards that work well in all other browsers. You can turn the tide by demanding more from Microsoft and by using a better alternative Web browser. I recommend and use Mozilla Firefox, but Apple Safari (Macintosh only) and Opera 8 are both worth considering as well.

Read the complete article

Stupid servlet problems

2005-08-01T14:59:00.000+02:00

Been chasing my tail here for half an hour. Got a 404 when trying to format an EDI message through my EdiFormatter application which helps me reading those formats. No matter what I did it gave me a 404 till I tried it locally and saw it couldn't find the class. Ahhrrrr.....changed package but forgot to update the web.xml. Ok well, if you've searched long enough for a stupid problem then you'll figure them out easier and faster next time you'll encounter them.

Passed SCEA

2005-07-15T09:49:00.000+02:00

Yesterday I've finally gotten the result back from the final (3rd) part of my SCEA (Sun Certified Enterprise Architect) exam. And the results of the sun jury are .... passed with 90% Yahoo

Split down results are

Class Diagram 44/44

Component Diagram 34/44

Sequence Diagrams 12/12

The result on the Component diagram was kind of expected as there's a number of ways to organise these (by tier, by package,...) since there's no one way of doing it I guess there's where I lost points.
But well I'm happy, petty however that you don't receive any feedback on the test, like this is how you should do it. But well if you come to think of it, that the same way when we were in school. I hated that system then already. Ok you've done the exam, but the actual purpuse is to LEARN something. By doing the exam, they only TEST you've learned something.
Maybe they've should have something like a detailed evaluation, but by then the money is already payed so I guess it doesn't matter for them anyway.

VRT doing PODCasting

2005-07-07T11:30:00.000+02:00

Through the Wouter.net Blog I heard that VRT is doing PODCasting. Hmm seems kinda strange with music industry trying to ban downloaded mp3's from the internet. Of course you could just as well tape it and encode it. But to actually make it public... Well at least they have the rights to broadcast music. So it must be legal.

In any case here's the podCast url for De Afrekening

Here you can find the url to other podCasts from the VRT

[Dutch] Te gekke opnamen...

2005-06-15T10:14:00.000+02:00

Lelystad

En nog eentje om het af te leren...

Middelvinger

Working on patio

2005-06-09T10:03:00.000+02:00

Been working with my father on the patio last 2 days... Hard work, almost halfway... We're getting there..

A whole new meaning to VOIP ....

2005-04-10T23:15:00.000+02:00

Besides installing and trying out Ubuntu last couple of days' for the interested ones docs can be found here) I just read an article on slashdot where it appears that they've found something to know what you're about to say. What they appear to be doing is put some chip on the back of your neck. Finally some privacy for those mobile calls or even VOIP calls... Read here all about it

Brave Pinguin

2005-04-05T00:35:00.000+02:00

To open source or not too open source

2005-03-21T17:58:00.000+01:00

Quite often I encounter a (java) project and while using it I download the source to see how it does things. When looking into the source I often see usage of things like jakarta-oro, xerces, xalan, jdom, dom4j to name a few. As the current jdk1.5 contains an xml parser/xsl transformer/regex I often see myself getting rid of these dependencies as the native JDK ones are much faster. Only problem is, when I talk to the people developing it, they either don't answer at all (ok an old project) or they don't like the license of it (GPL or LGPL). The latter I can understand (well kinda) but the first put's me in some kind of dillema as it would be so much nicer to put an updated version back online to allow other people to use it. But since I'm not a lawyer and don't intend of becoming one, I'm kind of reluctant too.

So maybe someone has some other ideas regarding this.

Long live courier

2005-03-21T17:49:00.000+01:00

Phew, turned kind of hot yesterday as I was upgrading my mail server (Courier .47 to .49). After a recursive configure and make, things got messy when I started to optimise permissions (and hence increasing security). Issues I've encountered so far:

Public folders need the sticky bit, otherwise it's difficult to keep track who's done what.

Personal folders can remain under 1 account provided they have permissions 0700.(so no sticky bit there)

If you've tried your own email account long enough bashing it to pieces, Courier marks it as Temporarely Unavailable. Only thing to do then is just go into /var/track/ and remove your account in there.

The file respawnlo, can be modified to restart once every x days (finally found that)

maildirshared contains the public folders for everybody

besides those discoveries, I've never had a mailserver that good. I've tried qmail/courier-imap and sendmail/wu-imap and hopefully I don't start a religeous war here but much too difficult to install and to administer.

Pretty outrageous

2005-03-07T20:31:00.000+01:00

Although I normally don't post anything even remotely related to politics in here, I couldn't resist now.
Check this out:

Nice DHTML calendar

2005-03-07T20:15:00.000+01:00

can be found here.

Labels

2005-03-04T09:29:00.000+01:00

Never been much of a spec guys anyway. But this is kind of neat.

the Html tag "label" allows you to use a larger region to select checkboxes or radiobuttons. How?

Try out a couple of check boxes:

Without a label

With a label

To operate the first check box you have to check on that little box. To use the second all you have to do is click on the text that applies to it. A much
larger target and much easier to use. And of course they are not just
for check boxes, but everything (radio buttons, text fields / areas,
drop downs, select boxes, ...)

How automotic proxy discovery works...

2005-01-31T19:46:00.000+01:00

Always found it intriguing how browsers have this new feature called Auto-detect proxy settings for this network. Now I just found how easy it actually is to implement.

The only thing you have to do is:

add an A record called wpad and let it point to a webserver running on port 80

On the root of that webserver you locate a file that contains actually the same thing as the well-known proxy.pac file.

That's it. Your network is configured!!

Continuous Integration in motion

2005-01-24T18:26:00.000+01:00

If you want to see what continuous integration is all about check this out

See computers think

2005-01-23T15:33:00.000+01:00

In this very nice Chess game

Person Looks

2005-01-21T17:30:00.001+01:00

Just found a site where you can simulate how you will look like if you were a old person.
Nice to see how babies and young children will turn out.

Just tried it with my nephew to see what it gives below the
output. In my opinion besides the fact that he looks like he's been
playing in the mud the whole day, it could very well be like this.
It's actually quite easy just upload a picture mention where the eyes and mounth are and there you go.

If you want to try for yourself

Why George Bush isn't always as dumb as it seems

2005-01-20T13:13:00.000+01:00

Here's why

Some nice tools

2005-01-20T08:27:00.000+01:00

Over the last days I've found a couple of nice things :

Picasa2: a nice image viewer/editor (from Google) that allows you to quickly fix organise your photos. One minor thing is that they require you to export your photos when you actually want to save them. Positive points are that its freeware and doesn't contain any spyware.

Javascript session timeout preventer : (Can always come in handy)

<script>

function expireSession()

{

window.location = "index.jsp";

}

setTimeout('expireSession()', <%= request.getSession().getMaxInactiveInterval() * 1000 %>);

</script>

Google ignoring spam put onto a weblog. Since lots of spammers now use blogs to get their website higher in the ranking of Google (number of links you know), Google now announce a good initiative to ignore these kinds of links. Provided that the blog engines add an attribute (rel="nofollow") that actually informs the search engine to ignore that link altogether. Now eat this spammer!!

Google Images over the years

2005-01-07T13:33:00.000+01:00

Just found a linkregarding the images Google uses over the years when (inter)national events occur.

Here it is

Nice Quote

2005-01-04T22:08:00.000+01:00

“I love my friends and family. I hate their computers.”

[found on 7seconden.be]

JSF vs. Tapestry

2005-01-04T19:54:00.000+01:00

While doing the assignment for the architect exam (SCEA) I'm taking, I was challenged to try out the new JSF web framework.
While doing the first screen everything went amazing, editboxes mapping to a string in a 'managed bean' worked like a charm.

But then the fun only had to start, checkboxes...

One of the more commenly used controls on a webpage is without a doubt a checkbox/radiobutton. When you have to map a collection onto a some checkboxes to make a selection, you have to have make a subclass of your original class of your businessmodel in order to let the facesServlet set the item as being selected. Needless to say is that this kind of plumbing annoys developers to the full extend, since it requires having n more classes (n being the number of business model classes).

If you compare this to tapestry, you enter a complete new ballgame. Tapestry allows developers to iterate over a collection and set the instance of the current iteration in the backing bean. The isSelected property of the backing bean can use this item and remove it from the collection of move it to a collection of selected items. This is a huge advantage if you ask me. The number of lines needed to implement it is really limited to the max. Furthermore, once you get used to this twist of mind, you get to use it for other items too.

Second serious malpractice of JSF is the use of Lists!!!, yes java.util.List instead of generic java.util.Collection. Meaning if you use a Set in your domain model, you have to convert it into List in order to be useful into JSF. Here goes the plumber again.....BTW, you can use arrays, but unless you have a good reason, I wouldn't use them in a serious model.

Comparing it to the great product Tapesty is, quite simply it allows arrays/collections AND iterators...what can I say more.

Voila, so far my humble experience with both products. Most probably I won't have to tell you which product I'll choose If given the opportunity to choose one out of 2. If both problems could be solved JSF could be nice, certainly if you take the renderkits into account, since this could be the killer item for JSF. Renderkits would allow you to create an application for the web and use the same application on a linux console via a telnet renderkit;..
Mmmmm, wouldn't that be nice..

Happy NewYear!!

2005-01-01T09:26:00.000+01:00

Been sick like a dog yesterday (seems to be some kind of bug that goes around every year). Of course you couldn't wish for a better day, well hopefully the new year is better.
Happy New Year and a good health to all of you.

SCEA Part II (The sequal)

2004-12-28T02:52:00.000+01:00

Been doing UML diagrams (class and sequence diagram mainly) all day. Fjew, although reverse engineering of existing code shouldn't be too difficult I spend quite some time in looking why I did what. Now the only thing that I still need to do is create a component diagram and do the whole documentation part around it. Found out that Jude (a free UML tool) that is written completely in java released a new version.

BTW if you get a message regarding an incorrect character set, consider switching to FireFox

Our first Christmas Eve in our new house...

2004-12-26T17:20:00.000+01:00

Everyone was there, my parents, Caroline, Filip, Maxim and my brother Stijn. Already after the preliminaries some of us feeled like stuffed turkeys but nonetheless a successful evening. Although for some reason Caroline seemed to be infected by the same bug that infected my nephew Maxim. Here some pictures.

kerstdag04