"Building" Quality Code: An Ant Experience

Working with Robocode for almost a month now, you begin to see the tediousness of some of the tasks. Some of which include, waiting for a battle to end, making sure your code is up to standards, and importing another persons Robocode robot. The current topic for this week in my Software Engineering class is Quality Assurance and Build Technology. This past week I have become familiar with the build technology - Apache's Ant in combination with Apache's Ivy - Library-Level Dependency Management Tool, to eliminate the tedious tasks.

Together with Ivy's ability to download and store the necessary libraries, and the automated build technology that is Ant, I can battle, standardize my code, and package my robot for distribution, all without ever opening Eclipse or Robocode.

Although Ant is Java-based, the build files are written completely in the XML format which means 1) No Compilers and 2) Each file can be read as source code. By using Prof. Johnson's Da-Cruzer build, I adapted it to work with my robot, StrafeNShoot.

By using the following tools:

• PMD
• Checkstyle
• FindBugs
• jUnit

I can eliminate long hours of staring at code looking for any rules that might have been broken by using PMD, Checkstyle, and FindBugs tools. I also can eliminate waiting for a battle to end by creating a test to see if my robot can beat another by creating a jUnit test and asserting that it has done so. In my case, I adapted Prof. Johnson's jUnit test to assert that my robot will always beat SittingDuck.

The other tools such as "jar" and "dist" make it easy to distribute my robot so other's can easily extract and battle/examine my robot. Compared to the long and painful way of importing a new project into Eclipse, and making sure all the paths are set before you can Roborumble.

Once you get Ant and Ivy set-up, this is indeed an incredible tool to automate tasks. However, the initial set-up was not so pretty. The errors that I encountered were mostly from adapting Prof. Johnson's DaCruzer build. I had not replaced all instances of his initials with my own, and same for his robot name, therefore Ant was so kind to tell me what types of problems I had and I quickly made the corrections.

I did run into some Environment Variable problems. I kept getting a "Unable to find tools.jar" error message when trying to build. Ant also gave some feedback saying it was looking for tools.jar in "C:\Program Files\Java\jre6". After searching the web for solutions, I can across the solution at this thread: http://forums.sun.com/thread.jspa?threadID=757039 Essentially I needed to declare my JAVA_HOME variable to point to the jdk folder, and the folder itself, NOT the bin, and I also remembered Ant does not work well with spaces, so I relocated my Java file directly into the C:\. So my JAVA_HOME ultimately was defined as "C:\Java\jdk1.6.0_16".

When I finally got it to run, I did the all the tests as described by the assignment and ended up with just 1 error:

• Checkstyle - 1 error
• PMD - 0 errors
• FindBugs - 0 errors

I was amazed to read that my error was:

[checkstyle] C:\robocode-etm-strafenshoot\src\etm\StrafeNShoot.java:78: First sentence should end with a period.

My first sentence of the javadoc was missing a period. Something so simple, yet hard to spot, the Checkstyle tool found it in 3 seconds. The fact that I don't have to use a resource heavy IDE like Eclipse to run these tools, and can do so easily with just the command prompt, I find these tools extremely helpful and efficient. Not only can you check the quality of your work, but you can also fix your code so that it is quality based on informative feedback. Although it takes effort to set-up, once everything is set all you have to do is invoke a simple command and Ant will do the rest. =)

My automated packaged, version 1.1 StrafeNShoot can be downloaded here.