maven maven-3 maven-resources-plugin buildnumber-maven-plugin

Why isn't mvn resources:resources picking up buildNumber?

I've got a maven project that uses the buildnumber-maven-plugin. If I run mvn validate I see it's working:

[INFO] --- buildnumber-maven-plugin:1.3:create (default) @ myproject ---
[INFO] Executing: /bin/sh -c cd /Users/rob/Workspace/myproject && git rev-parse --verify HEAD
[INFO] Storing buildNumber: 5d315d8d1a43c3289fbf114c379fa1a3d3787044 at timestamp: 1477059166424

But if I run mvn resources:resources the filtered file does not pick it up:

[INFO] --- maven-resources-plugin:2.6:resources (default-cli) @ myproject ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource

The pom.xml has:

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

version.txt has:

${buildNumber}

But after maven runs, no filtering:

> cat target/classes/version.txt
${buildNumber}

The build number config in pom.xml:

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>buildnumber-maven-plugin</artifactId>
    <version>1.3</version>
    <executions>
        <execution>
            <phase>validate</phase>
            <goals><goal>create</goal></goals>
        </execution>

I don't know enough Maven. Shouldn't running the resources "goal" also get the buildNumber property?

Solution

There is a difference in the commands that you execute:

mvn validate executes the maven phase "valdate": meaning all phases that come before (in this case none)

mvn resources:resources is a shortcut for executing the goal "resources" on the resources plugin. Actually its a shortcut for executing: org.apache.maven.plugins:maven-resources-plugin:3.0.1:resources. These short names are resolved by maven and very typical for plugins in the Apache namespace.

As you can see on the maven life-cycle page the goal you may look for is: "mvn process-resources". That phase has a default plugin binding to "resources:resources" which will run the resource plugin. Since you execute a phase all phases before that will be run too, including the build number plugin.

The ":" indicates the difference for the maven command line.