I read in maven-surefire-plugin and default locale that Maven runs tests forked and thus might lose any locale you might have set.
Is there a way to run tests in Maven in forked mode and still retain locale?
-- EDIT --
So, to clarify a bit: It is fully possible to set language and region in System Properties using:
<systemPropertyVariables>
<user.language>en</user.language>
<user.region>GB</user.region>
</systemPropertyVariables>
And they are actually passed to the running process. This does not however set locale accordingly; locale remains as System Default.
Try this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<argLine>-Duser.language=en -Duser.region=GB</argLine>
</configuration>
</plugin>