In Maven, how can I dynamically build a property value at runtime?

Mojo’s Build-Helper Maven Plugin can help you out here.

There are a number of goals that can be used to help transform properties.

There is

• build-helper:regex-property

• build-helper:parse-version

• build-helper:released-version

Probably regex-property is the one you want, but if your version numbers conform to the “standards” the other two might save you.

To use the regex-property goal you would do something like

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>build-helper-maven-plugin</artifactId>
        <version>1.7</version>
        <executions>
          <execution>
            <id>regex-property</id>
            <goals>
              <goal>regex-property</goal>
            </goals>
            <configuration>
              <name>tag.version</name>
              <value>${project.version}</value>
              <regex>^([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9]+)\.(-SNAPSHOT)?$</regex>
              <replacement>V$1_$2_$3_P$4</replacement>
              <failIfNoMatch>true</failIfNoMatch>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  ...
</project>

Note: my regex might be slightly off so you should test the above.

Note: The property value will only be available for executions after the phase that this execution is bound to. The default phase that it is bound to is validate but if you are on a different lifecycle (e.g. the site lifecycle) the value will not be available.