Professional

I know, YAML with tabs does not exist. But: I indent everything with tabs, and I am always annoyed when I open YAML files and they use spaces for indentation. So here it is: tjyaml - YAML with tabs for Java. It is just a fork of jyaml, which uses tabs when creating yaml files and allows them when reading. The rule how tabs are processed is simple: One tab is one indentation.

I just finished the slides for my talk about "Architecture in Scrum". I will upload them here before the talk.

Off we go :) At the JAX, I will listen to the JSF tutorial on day one and to the agile track on day 2.

The Breakfast Food Cooker. Nice reading. I did not know it, even though it was written quite some time ago.

I started preparing my Android-Talks for the Mobile Developer Day in Erlangen, Germany. I will be giving 2 talks about Android Developmen, so if you want to hear me there, just register at the link above. My talks will be aimed at beginners, so if you have some Android experience you probably will not learn much from them.

Today I did a short evaluation of free profiling tools. I have used Yourkit Java Profiler for some years now, and I am a big fan of it, but I wanted to give the alternatives another try.

First I had a look at Eclipse TPTP. Last time I tried (3 years ago) I couldn't even get it to start on my Mac. This time I am working on a Windows PC, so I thought this could be better supported. I downloaded it using the update site for eclipse, and after a restart of eclipse I got a nice introduction screen saying that I can now profile applications. So, I right-clicked on a project, selected "Profile As -> JUnit Test", and: Nothing happened. Except that after some time an exception message said that the profiler timed out. So, TPTP still sucks. BTW, I tried to search for solutions, but in the discussion forums and mailing lists are no real hints how to solve this problem.

The other tool I tried was jvisualvm, which is included in Java 6. I started it, and it found some java applications running. I launched the unit tests, and connected jvisualvm to the running tests. I got profiling results, but found no way to analyze them. Compared to Yourkit, jvisualvm is just a toy.

What I've learned today is that Yourkit is definitely worth the money. My advice for anyone who needs a profiling tool is: Download the trial version of Yourkit. I bet you'll buy it after the 15 days ;)

Refactoring large parts of a complex software system can cause a lot of troubles. And it is difficult. And I am always afraid to do it. But we have a lot of automated unit tests, integration tests and user acceptance tests in my current project, so most of the time I am pretty confident that I can make it. Without destroying any major feature.

Some days ago, I had a discussion with my co-workers whether we should start a large refactoring or not. Some were against it because of our tight schedule. We are committed to deliver working software at the end of the sprint, and we are committed to deliver the selected sprint backlog. And refactoring that part of the program would affect a lot of existing functionality, and all the committed user stories for the sprint.

After this discussion I really was not sure anymore if the refactoring would be a good idea right now. But it was absolutely necessary. We had a lot of code duplication. Some classes were used but not needed anymore, because the functionality could have been added to their base class. Responsibilities of one object were distributed over several classes.

Yesterday, despite all doubt, I started the refactoring. Today before noon I had outlined the basics so my co-workers could build on it. Shortly after that all unit- and integration-tests were green again. I started tomcat and tested the Application - all existing functionality still worked.

Implementing the current user story was really easy using the new design, and the next will be easier than before the change too. The refactoring was really successful - Everything still works and we have earned a quick win. And there were so many good arguments against starting it.

It's all about courage. (One of the 5 values)

Last week I attended a "Certified Scrum Master Training" in Linz (Austria). It was held by Christoph Mathis and Andreas Wintersteiger. Today I have completed the exam, and so now I am:

The Success of MultiTouch is a Lie by Josh Marinacci - very interesting reading. Like just about everything on Josh's blog. So everybody who doesn't read it yet: Read Josh on Design. It's great.

I just booked the flight to London and the Hotel (Notting Hill Gate Hotel) for my Stay at London. I will arrave on 2010-02-17 and visit the JAX London on 2010-02-22 and 2010-02-23. Departure is on 2010-02-24. If somebody wants to meet me there: Feel free to cantact me - the details can be found on the main page.