Java: Maven: get pom.xml information in properties file (mercurial hash as version)

Question

Im facing the following problem: I want to integrate the mercurial hash into my java project. I want to integrate it in the name of the generate file (a debian package) and I also want to have a file like version.properties where I can access the mercurial hash.

I know that there are a lot of similiar questions, but I read through them and somehow Im not able to solve my problem.

I use buildnumber-maven-plugin for retrieving the mercurial hash. I then integrate it in the version. The debian package is then generated with this hash when I run mvn clean install This is working so far.

<version>project-${buildNumber}</version>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>buildnumber-maven-plugin</artifactId>
            <version>1.0</version>
            <executions>
                <execution>
                    <phase>validate</phase>
                    <goals>
                        <goal>create</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

What I am missing is the buildNumber.properties file, which should be generated automatically by the plugin. I cant find it anywhere. So I decided to write my own properties file. I created one in src/main/resources and I added a property to my pom.xml. Here are the snippets:

pom.xml

<properties>
    <merc.version>${buildNumber}</merc.version>
</properties>

version.properties

version=${buildNumber}
version2=${merc.version}

I run then mvn clean install from cmdl. But when I open my version.properties file from command line with less, I see the content as plaintext like written above. The properties are not replaced with real content. I only see version=${buildNumber}, and so on.

Also, the file "pom.properties" which should be generated by maven does contain a very old version from one month ago. I dont understand what to do to update it.

Please, if any one could help me, that would be great :-) Thank you!

Answer 1

You have to activate filtering for the resources you wan't to be filter in that case this means:

<build>
 <resources>
    <resource>
      <directory>src/main/resources/version/</directory>
      <filtering>true</filtering>
    </resource>
  </resources>
...
</build>

If your version.properties files is correctly located under src/main/resources/version/ it will be filtered during the build process and will be copied to target/class/ ... where it should been replaced placeholders.