Maven: A Developer's Notebook

Tracking Project Activity

Tracking a project's activity is very important for end users/stakeholders. Several good indicators are available that can aid in tracking:

• The number of commits per day

• The number of additional unit tests added every day

• The evolution of test percentage coverage

• The mailing list activity

• The number of existing books on the project (mostly for open source projects)

• The number of committers

• The number of open issues in the project's bug tracker

• The number of years the project has been in existence

It would be very nice to have the equivalent of the Dashboard plug-in, but for project activity. This could provide a global project activity score à la SourceForge project activity percentage (e.g., http://sourceforge.net/project/stats/?group_id=15278).^[4] Unfortunately, such a comprehensive plug-in does not yet exist! Instead, you have several ad hoc possibilities:

• Use the StatCVS-XML plug-in to analyze a CVS repository and generate statistics.^[5] Unfortunately, such a tool doesn't exist for Subversion yet, but it won't be long before one does.

• Use the Developer-Activity and File-Activity Maven plug-ins that respectively report on developer commits and files containing the most changes, within a given date range.

Let's discover how to use these plug-ins.

How do I do that?

To use the StatCVS-XML plug-in you must install it, as it's not part of the default Maven distribution. Install the plug-in from http://statcvs-xml.berlios.de/, following the installation steps described in the Appendix A and in Chapter 6. You'll also need to ensure you have a command-line CVS client installed, as the plug-in is using the Ant cvs task to gather CVS logs for your project.

Using the plug-in cannot be simpler: add the maven-statcvs-plugin report to the reports section of your project's POM and run maven site. Myriad reports are generated, but here are a few that you should know more about in order to understand a project's activity. Figure 4-10 shows the commit activity per author and the aggregated activity over the whole lifetime of the Jakarta Cactus project.

Figure 4-10. Commit activity over time

Another very interesting report shows changes brought to a project over time, module by module, as shown in Figure 4-11 for the StatCVS-XML project itself.

Figure 4-11. Changes to the StatCVS-XML project over time, module by module

The goal here is not to take you through a full-length tutorial of StatCVS-XML, but rather to show you its power and how you can integrate it in a Maven project. You are strongly encouraged to explore it on your own at http://statcvs-xml.berlios.de/.

Although StatCVS-XML generates developer and file activity reports, it's still interesting to find out how to use the Developer-Activity and File-Activity plug-ins, as they also support Subversion. To use them, simply add them as usual to your POM. Let's do that on qotd/core/project.xml:

  <reports>
    <report>maven-developer-activity-plugin</report>
    <report>maven-file-activity-plugin</report>
    [...]

Running maven site generates the reports shown in Figure 4-12 and Figure 4-13.

Figure 4-12. Developer activity showing number of commits and files modified

Figure 4-13. Files which have been changed recently, ordered by change frequency

Both of these reports internally use the Changelog plug-in that you'll learn about in the next lab. You can configure them by using Changelog plug-in properties, such as the maven.changelog.range property that controls the report timeframe.

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^[4] SourceForge's current ranking formula is: log (3 * # of forum posts for that week) + log (4 * # of tasks ftw) + log (3 * # bugs ftw) + log (10 * patches ftw) + log (5 * tracker items ftw) + log (# commits to CVS ftw) + log (5 * # file releases ftw) + log (.3 * # downloads ftw).

^[5] Unfortunately, no such tool exists for Subversion—but it won't be long before one does.