Setting timezone for maven unit tests on Java 8

Question

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?

Answer 1

Short answer

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> 

Long answer

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>