Bill of Materials (BOM)

Bill of Materials (BOM)¶

A “Bill Of Materials” is a special Maven descriptor that defines the versions of a set of related artifacts.

To import the driver’s BOM, add the following section in your application’s own POM:

<project>
  ...
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>com.scylladb</groupId>
        <artifactId>java-driver-bom</artifactId>
        <version>4.7.0</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

This allows you to omit the version when you later reference the driver artifacts:

<project>
  ...
  <dependencies>
    <dependency>
      <groupId>com.scylladb</groupId>
      <artifactId>java-driver-query-builder</artifactId>
    </dependency>
  </dependencies>

The advantage is that this also applies to transitive dependencies. For example, if there is a third-party library X that depends on java-driver-core, and you add a dependency to X in this project, java-driver-core will be set to the BOM version, regardless of which version X declares in its POM. The driver artifacts are always in sync, however they were pulled into the project.

BOM and mapper processor¶

If you are using the driver’s object mapper, our recommendation is to declare the mapper processor in the annotationProcessorPaths section of the compiler plugin configuration. Unfortunately, <dependencyManagement> versions don’t work there, this is a known Maven issue (MCOMPILER-391).

As a workaround, you can either declare the mapper processor as a regular dependency in the provided scope:

  <dependencies>
    <dependency>
      <groupId>com.scylladb</groupId>
      <artifactId>java-driver-mapper-processor</artifactId>
      <scope>provided</scope>
    </dependency>
  </dependencies>

Or keep it in the compiler plugin, but repeat the version explicitly. In that case, it’s probably a good idea to extract a property to keep it in sync with the BOM:

<project>
  <properties>
    <java-driver.version>4.7.0</java-driver.version>
  </properties>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>com.scylladb</groupId>
        <artifactId>java-driver-bom</artifactId>
        <version>${java-driver.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>
  <dependencies>
    <!-- Regular dependency, no need to repeat the version: -->
    <dependency>
      <groupId>com.scylladb</groupId>
      <artifactId>java-driver-mapper-runtime</artifactId>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <annotationProcessorPaths>
            <!-- Annotation processor, can't use the BOM => explicit version -->
            <path>
              <groupId>com.scylladb</groupId>
              <artifactId>java-driver-mapper-processor</artifactId>
              <version>${java-driver.version}</version>
            </path>
          </annotationProcessorPaths>
        </configuration>
      </plugin>
    </plugins>
  </build>