[discuss]maven.version conflict in pom.xml & system property

[lanmaoxinqing]

We have the maven.version property configed in root pom.xml, to specify the base maven version we used for mvnd.

    <properties>
        <maven.version>3.8.1</maven.version>
    </properties>

And we also setup this property in DaemonMavenCli.java, for --version usage to display system maven version, i guess?

        String mavenVersion = buildProperties.getProperty(CLIReportingUtils.BUILD_VERSION_PROPERTY);
        systemProperties.setProperty("maven.version", mavenVersion);

It works fine in each designed satuation, until i try to use maven.version in xxx.proerties files. maven.version defined in pom.xml is overrided by system property, according to Spring Externalized Configuration, so i can't get the maven version we use for mvnd.

Is this an expected feature, or a bug ?

[ppalaga]

It works fine in each designed satuation, until i try to use maven.version in xxx.proerties files.

Which xxx.properties files do you mean?

maven.version defined in pom.xml

Which pom.xml?

is overrided by system property, according to Spring Externalized Configuration, so i can't get the maven version we use for mvnd.

Not sure at all, how Spring Externalized Configuration comes into game?
Could you perhaps use an example to explain what you mean?

[lanmaoxinqing]

Oh, sorry for my ambiguous description troubled you. I'm aim to build different mvnd for each maven version, so i need to get the maven version defined in pom.

Let's show the test code first...
lanmaoxinqing@f2426a8

Here is the github action result
https://github.com/lanmaoxinqing/mvnd/actions/runs/1466173659

Download the zip and go into mvnd-0.7.1-SNAPSHOT-linux-amd64.jar:/mvn/lib/ext/mvnd-common-0.7.1-SNAPSHOT.jar:/org/mvndaemon/mvnd/common/build.properties, you will find the mvnVersion is 3.6.3, and the value i expect is 3.8.3

Here is the detail below:

Which pom.xml?

https://github.com/mvndaemon/mvnd/blob/85e4d0cf2a6c6de3c34a12c582c96ba0aa4a0baa/pom.xml#L49

Which xxx.properties files do you mean?

https://github.com/mvndaemon/mvnd/blob/85e4d0cf2a6c6de3c34a12c582c96ba0aa4a0baa/common/src/main/resources/org/mvndaemon/mvnd/common/build.properties#L22

I try to add a property named mvnVersion after it using maven.version property defined in pom.xml

mvnVersion=${maven.version}

how Spring Externalized Configuration comes into game?

https://github.com/mvndaemon/mvnd/blob/85e4d0cf2a6c6de3c34a12c582c96ba0aa4a0baa/daemon/src/main/java/org/apache/maven/cli/DaemonMavenCli.java#L1438-L1443

maven.version property is also defined in system property, and overrides the same property in pom.xml.

When i build mvnd with maven 3.6.3 and maven.version defined in pom.xml is 3.8.3, the mvnVersion finally i get is 3.6.3, rather than 3.8.3.

[gnodet]

I don't think this is a mvn issue as maven defines those system properties explicitely:
https://github.com/apache/maven/blob/8456294977b40660ce37db853de344f0d26ee46d/maven-embedder/src/main/java/org/apache/maven/cli/MavenCli.java#L1655-L1659