The Tech Blog of Ken

Moving from Ant to Maven

I've made the switch from Ant to Maven at work. Ant is an extremely flexible and powerful tool, but I find that most of the time it's TOO flexible when you are working in an environment where you are doing complex builds.

Thinking back over half a decade of Ant scripts, I realize that I always spend a lot of time when I join a new project trying to understand a whole set of different Ant scripts and then getting all of them to look and work in a consistent way across all the components I'm building. Maven uses a standardized build process with hooks at each step in the process for you to customize or add your own behavior. Think about all those standard things you do for a build. Compile some source code, run some unit tests, create a test report, then create a package (jar, ear, whatever). A simple Maven build gives you all that stuff right out of the box, even without having to write any scripts.

The Maven home page uses some intimidating language - what's all this about a "Project Object Model"? That's enough to scare off any prospective user. A POM is simply an XML file where you put the basic information about your builds - jar dependencies, file names, etc - all the same stuff you would have in an Ant build script. It's all declarative, so you don't have to worry about the order of things (sounds like Ant in the early days). Maven uses standard conventions for directory structures to keep things simple to configure (no more arguing with your coworkers about whether to put your source code in 'src' or 'source' or 'java'), and to keep things the same between different build scripts. Of course, you can override these configurations, but it's better to go with the standard just for consistency.

I think some people are in a pretty good comfort zone with Ant and are afraid of learning a new tool for builds. But overall, I think it's faster and easier to start from scratch with Maven. If you're the type of person who likes the use of "convention over configuration" in Rails, then Maven is for you.

And BTW, if you're working with Rails, rake and Capistrano are no-brainers.

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Formula One Live Timing - a useful java applet, for once

This may not be of much interest to North American racing fans, what with the popularity of NASCAR and the latest F1 fiasco at Indy, but java developers should appreciate it. F1 Live Timing is just the kind of useful applet that was envisioned a decade ago when applets were the way of the future. Too bad most of the java applets we saw along the way were nearly useless.

Besides the fact that it's a nifty applet, the live timing screen really enhances the experience of watching a Formula One race on TV. I imagine that the screens here aren't too different from all those screens that the team bosses see from pit lane.

I've captured a few screenshots of the live timing applet in action during Sunday's F1 race in Hockenheim, Germany.

Instead of a page that keeps refreshing, you get live data that's updated in (near) real-time. (I suppose this could have easily been done with AJAX, though). On the right side of the screen you see a scrolling commentary.

This is the weather tab. The yellow arrow in the lower left rotates to show the wind direction, and the graph shows the barometric pressure over time.

Now for the real action. Here's a capture of the Lap Chart right after Kimi Raikkonen's car froze up. This screen is a really interesting way to visualize the progress of a race, and really makes watching the race more interesting. Even when watching a race on TV, it's pretty hard to keep track of the order of the cars, especially once they start heading into the pits. The graphical view above shows (in real time) the position of each car and which lap each car is on. The cars are shown in starting order on the left side of the screen. You can follow the progression of each driver throughout the race (check out Montoya, the car at the bottom, as he moves up the ranks). It's neat how the boring laps (where no position changes occur) are dropped in order to compress the amount of data on the screen. You can see Kimi's line end at lap 36 and Alonso's line move up to take first. Sorry Kimi!

The relatively simple graphics could have been easily accomplished with Flash, so I'm not sure why they decided to use java. Maybe Flash wasn't up to the task of handling a data stream like this? I don't know much about Flash, so I can't comment on that.