Meld and Mercurial 3 way Merge is Mental

- 1 min read

By default Meld’s 3 way merge combined with Mercurial merges into the left panel. To make it merge into the middle panel add the following to .hgrc file

[merge-tools]
meld.executable = meld
meld.args = $local $base $other -o $output

java.lang.ClassNotFoundException: org.apache.log4j.FileAppender

- 1 min read

Hopefully this will stop someone from wasting a day of their life…
If you pass in the following when you start your Java application:

java -Dlog4j.configuration=file:///some/path/log4j.properties

And that file contains a class that is not on the class path

log4j.appender.myAppender=biz.minaret.log4j.DatedFileAppender
log4j.rootLogger=error, myAppender

Then due to the log4j static initialisers you will not see an error for the class in question but instead:

Caused by: java.lang.ClassNotFoundException: org.apache.log4j.FileAppender
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)

Unfortunately for me this was caused by a transitive dependency changing in Maven. Damn you Maven/Log4J

Crazy fast build times (Or when 10 seconds starts to make you nervous)

- 10 mins read

Firstly this is not just my effort but my team and organisation.
Secondly the usual rules apply, this is expert advise and what works for me will very probably cause your whole production stack to blow up and kill people.
Lastly this is long so skip to the bit you care about or come along and chat at QCon London 2012

Well lets answer the obvious questions:
“Can this work for real apps or just fun stuff?” Yes real apps old and new.
“Does it need to be greenfield?” No but it takes a long time (months) to get builds down on old codebases.

Read More…

99 Bottles of Beer in Totallylazy

- 1 min read 
import static com.googlecode.totallylazy.Runnables.printLine;
import static com.googlecode.totallylazy.lambda.Lambdas.n;
import static com.googlecode.totallylazy.lambda.Lambdas.λ;
import static com.googlecode.totallylazy.numbers.Numbers.decrement;
import static com.googlecode.totallylazy.numbers.Numbers.range;

public class BottlesOfBeer {
    // Run with -javaagent:enumerable-java-0.4.0.jar -cp:totallylazy-598.jar:enumerable-java-0.4.0.jar
    public static void main(String[] args) {
        range(99, 0).map(λ(n, verse(n))).each(printLine("%s of beer on the wall.\n"));
    }

    private static String verse(Number number) {
        if (number.equals(0))
            return "No more bottles of beer on the wall, no more bottles of beer.\n" +
                   "Go to the store and buy some more, 99 bottles";
        return String.format("%s of beer on the wall, %1$s of beer.\n" +
            "Take one down and pass it around, %s", bottles(number), bottles(decrement(number)));
    }

    private static String bottles(Number number) {
        if (number.equals(0)) return "no more bottles";
        if (number.equals(1)) return "1 bottle";
        return number + " bottles";
    }
}

Slow TrackPoint on Dell Precision M6500 under Ubuntu 10.10

- 1 min read

If you have a Dell Precision M6500 with a Synaptic TouchPad + TrackPoint) (rather than an ALPS version) and you are running Ubuntu 10.10 you may find the TrackPoint / TrackStick / Nipple is being detected as a standard PS/2 Generic Mouse and this is causing the movement to be very slow.

You can check this by typing:

xinput list

If you see something like this:

Virtual core pointer                    	id=2	[master pointer  (3)]
↳ Virtual core XTEST pointer              	id=4	[slave  pointer  (2)]
↳ SynPS/2 Synaptics TouchPad              	id=11	[slave  pointer  (2)]
↳ PS/2 Generic Mouse                      	id=12	[slave  pointer  (2)]

As you can see the TrackPoint is not listed and as such you wont see it in any of the configuration screens.

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Crazy Talk - Holistic Web Testing - Some forces...

- 1 min read

So given the above, the forces I am trying to balance are

  • Make it easy for people to do the right thing, hard to do the wrong thing.
  • Make it valuable (Finds more bugs than false alarms)
  • Make it resilient (Allows me to refactor like the true crazy person I am)
  • Make it fast (Magnify it’s value rather deminishing it)
  • Make it good enough (Give me enough confidence to do more crazy stuff but don’t become dogmatic)
  • Allow people to do what they are good at

Next I’ll talk about how the default setup I use to do, in-memory, out of container testing.