Locales vs. consistent builds

[MOJO-1193] Locale support for formatting dates and times

I wanted to use the Maven buildnumber plugin to generate a date string like "31-Jul-2008" for inclusion in an automatically generated release notes document. This way I could minimize the amount of manual tweaking I need to do when publishing the release.

This was easy enough (though quite verbose) to achieve:

    <plugin>
      <groupId>org.codehaus.mojo</groupId>
      <artifactId>buildnumber-maven-plugin</artifactId>
      <configuration>
        <format>{0,date,dd-MMM-yyyy}</format>
        <items>
          <item>timestamp</item>
        </items>
      </configuration>
      <executions>
        <execution>
          <phase>validate</phase>
          <goals>
            <goal>create</goal>
          </goals>
        </execution>
      </executions>
    </plugin>

Unfortunately, the resulting date string would be the expected "31-Jul-2008" on one computer, but "31-heinä-2008" (in Finnish) on my laptop. Instead of changing the settings of my laptop I wanted to explicitly set the locale that the buildnumber plugin should use when formatting the date. I wasn't too surprised that the required functionality didn't yet exist (it's quite common for people to forget about locales), but luckily it wasn't too hard to add. Thus MOJO-1193.

With my patch the required configuration becomes:

      <configuration>
        <format>{0,date,dd-MMM-yyyy}</format>
        <locale>en_US</locale>
        <items>
          <item>timestamp</item>
        </items>
      </configuration>

Consistency is good.