This article is a repost of my comments to the question on how to implement hashCode and equals on stackoverflow There are some issues worth noticing if you’re implementing hashCode and equals for classes that are persisted using an Object-Relationship Mapper (ORM) like Hibernate. If you didn’t think this topic is stupidly overcomplicated already! Lazy loaded objects are subclasses If your objects are persisted using an ORM, in many cases you will be dealing with dynamic proxies to avoid loading object too early from the data store.

This is a rough Norwegian language translation of the article JKE Day 1: Toyota Kyushu - The Manufacturing Ballet by Kevin Meyer (improvements on the language are very welcome, comments on the contents should go to Kevin). The reproduction has been authorized by the author. Unlike the rest of my site, this article is not available under creative commons license. Jeg kom over en artikkel som demonstrerte hvor bemerkelsesverdig lean production system kan være.

When I encounter a system that has already been in development or production for a while, the first sign of real trouble is always a dirty log. You know what I’m talking about. When clicking a single link on a normal flow on a web page results in a deluge of messages in the only log that the system provides. Too much logging is as useless as none at all.

I’m going on the road again. This time it’s not far, just to Trondheim for a seminar for the Norwegian computer association that I will be giving together with Aslak Hellesøy on agile development and testing. This will be similar to our line-up at JavaZone: Aslak will cover “how to make the correct software”, and I will cover “how to make the software correct”. Hopefully, we’ll make a few test managers think and a few others angry.

The alumni organization from my old university is arranging a debate about open source, and I’ll be moderating. The debate will be next Wednesday at Scotsman in downtown Oslo. There will be a four person panel, with two skeptics and two open source fans. So far, the panel looks as follows: Heidi Arnesen Austlid, Friprogsenteret Per Hove, Oracle Norge Shahzad Rana, Questpoint An exciting surprise! The event will be held in The Scotsman, where they sell beer!

The Norwegian Agile User Group conference, Smidig 2008 was on Thursday and Friday. Both days started with three hour sessions of Lightning Talks, followed by three hours of open space work groups after lunch. We have been very happy with the format. The lightning talks give people food for thought. The best lightning talks are formulated around a provoking hypothesis. Kai Gilb talked about how we should focus on value instead of function.

The videos from JavaZone are up. Here’s my talk about Extending Continuous Integration, which talks about how I automatically run system level integration tests after every build.

In the middle of changing jobs, I have also been quite busy with the last minute preparations for the Smidig 2008 conference for the Oslo Agile user community (“smidig” being the closest Norwegian translation of “agile”). The conference be two days of lightning talks before lunch and open spaces after lunch. The program is in the final stages of being finalized as we speak. There are still a few open seats.

It’s been a while since I promised to write top five unit testing tips, so I guess I should better start writing #2. As with my first example this one is based on a real-life story. Your code is worth nothing if it can’t be tested. Change your code to make it more testable. In my last project, we used a pipes and filter architecture, with messages being passed forward through a chain of services.

I don’t normally post just a link to another blog, but More thinking about “Agile” vs “Waterfall” by Jason Yip is just too important. It the most well-argued, well-referenced, short post I’ve seen about the subject. Here’s a taste: Be careful about saying that Waterfall is more disciplined. The waterfall model is simple and structured but the “discipline” is in following prescribed steps as opposed to “discipline” in thinking. The second kind of discipline is by far the more important.