Managing Maven plugin versions with Spring Boot BOM

Question

I have a Maven POM for a Spring Boot project. The POM imports the Spring Boot BOM. Now I want to customize the configuration of a Maven plugin, say, mvn-compiler-plugin. I'd like to use the plugin version maven-compiler-plugin.version dictated by the spring-boot-dependencies BOM.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>ch.ge.mygroup</groupId>
    <artifactId>myartifact</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <spring-boot.version>2.4.2</spring-boot.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <!-- Spring Boot BOM -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven-compiler-plugin.version}</version>
                <configuration>
                    <!-- some particular config here -->
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

But this does work: I come up with a Maven error:

[ERROR] [ERROR] Some problems were encountered while processing the POMs:
[ERROR] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin must be a valid version but is '${maven-compiler-plugin.version}'. @ line 31, column 26

So I have to explicitly specify the version of the Maven plugin, which I want to avoid.

In summary:

Using

<plugin>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>${maven-compiler-plugin.version}</version>
  <configuration>
    <!-- some particular config here -->
  </configuration>
</plugin>

yields a Maven error.

Using

<plugin>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.8.1</version>
  <configuration>
    <!-- some particular config here -->
  </configuration>
</plugin>

works, but prevents me from using the version (3.8.1) dictated by the Spring Boot BOM.

Using

<plugin>
  <artifactId>maven-compiler-plugin</artifactId>
  <configuration>
    <!-- some particular config here -->
  </configuration>
</plugin>

works, but uses an old version (3.1) of the plugin.

How can I avoid to explicitly specify the plugin version and instead implicitly use the plugin version provided in the Spring Boot BOM?

Answer 1

If you want to override Spring Boot dependencies by simply updating properties, you have to specify the parent POM instead of importing:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>ch.ge.mygroup</groupId>
  <artifactId>myartifact</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-dependencies</artifactId>
    <version>2.4.2</version>
    <relativePath/>
  </parent>

  <properties>
    <spring-boot.version>2.4.2</spring-boot.version>
    <maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
  </properties>

  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>${maven-compiler-plugin.version}</version>
        <configuration>
          <!-- some particular config here -->
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>