How do I set the timezone for unit tests in maven surefire on Java 8?
With Java 7 this used to work with systemPropertyVariables
like in the following configuration, but with Java 8 the tests just use the system timezone.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<systemPropertyVariables>
<user.timezone>UTC</user.timezone>
</systemPropertyVariables>
Why is that, and how do I fix it?
Java now reads user.timezone
earlier, before surefire sets the properties in systemPropertyVariables
. The solution is to set it earlier, using argLine
:
<plugin>
...
<configuration>
<argLine>-Duser.timezone=UTC</argLine>
Java initializes the default timezone, taking user.timezone
into account the first time it needs it and then caches it in java.util.TimeZone
. That now happens already when reading a jar file: ZipFile.getZipEntry
now calls ZipUtils.dosToJavaTime
which creates a Date
instance that initializes the default timezone. This is not a surefire-specific problem. Some call it a bug in JDK7. This program used to print the time in UTC, but now uses the system timezone:
import java.util.*;
class TimeZoneTest {
public static void main(String[] args) {
System.setProperty("user.timezone", "UTC");
System.out.println(new Date());
}
}
In general, the solution is to specify the timezone on the command line, like java -Duser.timezone=UTC TimeZoneTest
, or set it programmatically with TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
.
Full'ish example:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
... could specify version, other settings if desired ...
<configuration>
<argLine>-Duser.timezone=UTC</argLine>
</configuration>
</plugin>
</plugins>
</build>