A collection of thoughts, ideas and rants inspired by my career in the fintech and banking industry.

How to show which .hgrc Mercurial is using

 Posted on November 22, 2012  |  Craig Pardey

Mercurial loads a bunch of different configuration files and overlays their values on top of each other. The hgrc man page shows the order in which these files are loaded. I encountered an issue recently where I knew that hg was using an erroneous setting but I had no idea where the setting was coming from. The magic answer is hg --debug showconfig This will output all the current settings, along with the name of the file that it got each setting from. [Read More]
Mercurial 

How to take local in Mercurial without a merge conflict

 Posted on November 12, 2012  |  Craig Pardey

When there’s a merge conflict in Mercurial, TortoiseHG will give you the option to ’take local’ or ’take other’ in addition to resolving the conflict.

However, sometimes you may want to ’take local’ or ’take other’ when there’s no merge conflict.

To take local:

hg merge --tool internal:local <rev>

To take other:

hg merge --tool internal:other <rev>
Mercurial 

Broken Generics

 Posted on November 7, 2012  |  Craig Pardey

Given the following code Map<String, String> map = new HashMap<String, String>(); map.put("123", "value"); Integer key = Integer.valueOf(123); String actual = map.get(key); What is the value of “actual”? Compilation error - key should be a String “value” null Answer: null This blew me away. The whole point of type-safe collections was supposed to provide compile-time checking. However, the only generics method on the Map class is put(K, V). So calling get(Object) doesn’t cause a compilation error, but merely returns null. [Read More]
Java 

Slow Mercurial clone

 Posted on October 25, 2012  |  Craig Pardey

I recently set up a Mercurial server (Windows, Apache, ActiveDirectory and hgweb.wsgi). However, cloning our 1Gb repository took an hour or more and often failed. The only information in the Apache log was mod_wsgi (pid=1234: Exception occurred processing WSGI script 'C:/hg/hgweb/hgweb.wsgi' IOError: failed to write data The solution was to disable compression by adding the following lines to hgweb.config [server] preferuncompressed = true By default, Mercurial will compress everything before sending it down the pipe. [Read More]
Mercurial 

Error creating logs directory in Apache Tomcat

 Posted on October 1, 2012  |  Craig Pardey 

java.util.logging.ErrorManager: 4: Unable to create [c:pache-tomcat-7.0.30 -Dcatalina.home=c:pache-tomcat-7.0.30\logs\]

I was getting this error recently, and found that it was caused by having a trailing backslash on my CATALINA_HOME variable.

i.e.
Incorrect:

set CATALINA_HOME=c:pache-tomcat-7.0.30\

Correct:

set CATALINA_HOME=c:pache-tomcat-7.0.30
Tomcat 

Anti-pattern: Re-use through inheritance

 Posted on July 19, 2012  |  Craig Pardey

When I first started programming in object oriented languages I used inheritance to reduce code duplication. You know the deal - you have two classes that do the same sort of thing so you create an abstract superclass and extract the common code into methods in the superclass. Voilà. No more duplicated code. But I was unwittingly creating an untestable codebase. I have worked extensively with dependency injection containers over the last five years and have begun to rely on the clean code they facilitate. [Read More]
Anti-pattern 

JUnit categories with Maven

 Posted on July 14, 2012  |  Craig Pardey

------------------------------------------------------- T E S T S ------------------------------------------------------- [INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ junit-categories --- [INFO] com.craigpardey:junit-categories:jar:1.0-SNAPSHOT [INFO] +- org.jmock:jmock-junit4:jar:2.6.0-RC2:test [INFO] | +- org.jmock:jmock:jar:2.6.0-RC2:test [INFO] | | \- org.hamcrest:hamcrest-library:jar:1.3.RC2:test [INFO] | \- junit:junit-dep:jar:4.4:test [INFO] \- junit:junit:jar:4.10:test [INFO] \- org.hamcrest:hamcrest-core:jar:1.1:test See how jmock-junit4 depends on junit-dep:4.4, and that it appears before JUnit 4.10? That’s the cause of the error above. You can either exclude each of these conflicting dependencies or you can make sure that the versions of JUnit and/or JUnit-dep appear first in the classpath. [Read More]
JUnit 

Mercurial ignore file for Maven projects

 Posted on June 21, 2012  |  Craig Pardey

I find it hard to remember all the .hgignore settings for a new Mercurial repository that I need, so here’s a bootstrap version

syntax: glob
.hgignore
*/target/**
*/.settings/**
*/.classpath
*/.project
*.log
*.orig
Mercurial 

No stand-up

 Posted on June 12, 2012  |  Craig Pardey

There was no stand-up this morning and it felt like my day never really started. It was my first day at my new job with CIBC and, even though I knew that the team was not agile before signing up for the gig, I had underestimated how much I depended upon our daily rituals practices at Intelliware. These practices provided a rhythm and cadence to the day that I had taken for granted. [Read More]
Agile 

Maven Release from Jenkins

 Posted on May 22, 2012  |  Craig Pardey

I encountered this error while setting up a Jenkins job to automate our Maven release process. [INFO] EXECUTING: cmd.exe /X /C "hg commit --message "[maven-release-plugin] prepare for next development iteration" c:\jenkins\jobs\Release\workspace\pom.xml" [DEBUG] abort: C:\Jenkins\jobs\Release\workspace\pom.xml not under root [ERROR] EXECUTION FAILED Execution of cmd : commit failed with exit code: -1. Working directory was: c:\jenkins\jobs\Release\workspace Your Hg installation seems to be valid and complete. Hg version: 2.0 (OK) Our Jenkins box runs on Windows. [Read More]
Maven  Jenkins