zhangjh/resolve-pom-maven-plugin

This Maven plugin creates in the initialization phase a copy of the original POM where all properties get resolved by its actual values. This substituted POM is used in the further processing. Especially it will be used when an upload to the local or remote repository takes place.

resolve-pom-maven-plugin

Motivation

As you might know Maven always uploads the original source pom.xml into the local and remote repository and does not replace the property placeholders by the actual values used during the build. However, sometimes it would be really useful if a resolved version would be uploaded. A typical usage scenario is to pass in the artifact version from the outside (e.g. by the central build server).

Use Case: Project Version Injection

A common requirement is to create an artifact built with Maven where the version name or suffix is determined by the build job. The widely spread approach to achieve this non Maven like behavior is to us a variable in the version element of the POM as shown in the following example:

<project>
  ...
  <parent>
    <groupId>my.group</groupId>
    <artifactId>parent</version>
    <version>1.0.${injectedBuildNr}</version>
  </parent>

  <artifactId>child</version>
  
  <properties>
    <injectedBuildNr>0-SNAPSHOT</injectedBuildNr>
  </properties>
  ...
</project>

Now Maven gets called by the build system with mvn clean deploy -DinjectedBuildNr=42 and everything seems to be working, as the artifact ends up at the correct location with the correct version in the local and remote repository. However, if you look inside the uploaded pom file you'll discover that the source POM file has been uploaded that still contains the {$injectedBuildNr} property. This will lead to errors when the artifact gets consumed by another Maven build as the dependency resolution will fail when searching for the parent with version 1.0.${injectedBuildNr}.

By using the resolve-pom-maven-plugin the resolved pom will be uploaded and everything works as desired.

Usage

The plugin provides just one goal named resolve-pom-props that creates a file named resolvedPom.xml that is located in the same directory as the original POM where all property placeholders got replaced by their actual values. This resolved POM will be uploaded into the local and remote repository.

Just add the following build configuration to your (parent) POM and the plugin will be executed in your build lifecycle:

  <build>
    <plugins>
      <plugin>
        <groupId>com.sap.prd.mobile.ios.maven.plugins</groupId>
        <artifactId>resolve-pom-maven-plugin</artifactId>
        <version>1.0</version>
        <executions>
          <execution>
            <id>resolve-pom-props</id>
            <goals>
              <goal>resolve-pom-props</goal>
            </goals>              
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

License

This project is copyrighted by SAP AG and made available under the Apache License 2.0. Please also confer to the text files "LICENSE" and "NOTICE" included with the project sources.