yah, use buildnumber-maven-plugin may be better.
one strange thing is I can't use ${buildNumber} in filter,
when I want to replace $BUILDTIME in the resource file.
such as:
in pom.xml
<properties>
<BUILDTIME>${buildNumber}</BUILDTIME>
</properties>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
<includes>
<include>Version.txt</include>
</includes>
</resource>
in Version.txt
build-time= ${BUILDTIME}
