maven-version-number-variable-in-manifest
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>${maven.war.plugin.version}</version>
<configuration>
<archive>
<manifest>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
</manifest>
<manifestEntries>
<Oxygen-Build-Version>A${maven.build.timestamp} ${project.version}</Oxygen-Build-Version>
</manifestEntries>
</archive>
</configuration>
</plugin>