This is a maven plugin that allows for developers and organizations to ban Maven artifacts. We are keenly aware of the capability in the maven-enforcer-plugin. Instead of simply generating an error when a banned artifact is referenced, this plugin prevents the artifact from being downloaded as well. This is crucial within certain organizations with strict security scans that crawl the Maven cache.

Usage

Here is an example of the primary reason why this plugin is useful.

<project>
    ...
    <build>
        ...
        <plugins>
            ...
            <plugin>
                <groupId>com.inteligr8</groupId>
                <artifactId>ban-maven-plugin</artifactId>
                <version>...</version>
                <extensions>true</extensions>
                <configuration>
                    <import>
                        <url>https://host:port/path/file.xml</url>
                        <artifact>groupId:artifactId:version</artifact>
                    </import>
                    <includes>
                        <artifact>
                            <groupId>...<groupId>
                            <artifactId>...<artifactId>
                            <version>...</version>
                        </artifact>
                        <artifact>
                            <groupIdRegex>...<groupIdRegex>
                            <artifactIdRegex>...<artifactIdRegex>
                            <version>...</version>
                        </artifact>
                        <artifact>com.inteligr8:ban-maven-plugin:[,1.0.0)</artifact>
                        <artifact>log4j:log4j</artifact>
                        <artifact>org\.springframe.+::[,4.0.0.RELEASE)</artifact>
                    </includes>
                    <excludes>
                    	   <artifact>
                    	       ....
                    	   </artifact>
                    </excludes>
                </configuration>
            </plugin>
            ...
        </plugins>
        ...
    </build>
    ...
</project>

The extensions elements is critical. Without it, the plugin does nothing for banning artifacts/dependencies. With it, the plugin is able to not only detect ban artifacts, but do it before they are downloaded. This keeps libraries from even reaching your local Maven repository cache.

Here is an example of the non-extension use case for the plugin:

<project>
    ...
    <build>
        ...
        <plugins>
            ...
            <plugin>
                <groupId>com.inteligr8</groupId>
                <artifactId>ban-maven-plugin</artifactId>
                <version>...</version>
                <extensions>true</extensions>
                <configuration>
                    ...
                </configuration>
                <executions>
                    <execution>
                        <id>clean</id>
                        <phase>clean</phase>
                        <goals><goal>purge-repo</goal></goals>
                    </execution>
                </executions>
            </plugin>
            ...
        </plugins>
        ...
    </build>
    ...
</project>

The purge-repo goal will remove all banned artifacts from your local Maven cache. It does not support groupIdRegex or blank groupId specifications. So any of those will not be purged/removed.

Configuration

If no includes are provided, then no artifacts will be banned. An included artifact is a banned artifact. An excluded artifact is not banned. It is the opposite of what you may think. If no excludes are provided, then no banned artifacts are granted an exception.

The artifact element supports the descriptive groupId/artifactId/version elements or the abbreviated colon-based notation. When using the colon-based notation, the group ID and artifact ID are treated as groupIdRegex and artifactIdRegex (see below).

If groupId or artifactId or version are not provided, they are ignored in the matching process. So it will match all applicable artifacts and the constraint will be only for what was specified. This means that <includes><artifact>:</artifact></includes> will ban every artifact and all their versions.

If groupId and groupIdRegex are both provided, only groupId is used. The same is true for artifactId and artifactIdRegex. The *Regex element values use standard Java regular expression parsing. If using regular expressions, remember to escape the dots (\.) in group IDs. If you do use groupIdRegex or use regular expressions in the colon-notation, the matching artifacts will not be purged using the purge-repo goal. So if you intend to use that goal, group ID regular expression matching needs be avoided.

The version element supports the standard Maven specification. You can match a specific version like 1.0.0. Or you can match all versions before 1.2.17 like [,1.2.17). You can match all future versions after 1.2.17 (inclusive) with [1.2.17,).

There is nothing stopping you from specifying two artifact elements with the exact same values. So you can ban multiple version ranges of the same artifact by using multiple artifact elements.

If you include all versions by omitting the version element, you can still exclude (un-ban) certain versions, like [1.2.17,).

Order does not matter. All include specifications are processed, followed by all exclude specifications.

Import

The import URL and artifact are to reference XML files that conform to the same configuration element as described here. In fact, the root elmenet of that XML should be configuration. It will only support the includes and excludes elements. so you cannot do recursive imports.

You can create a Maven pom packaging type project that deploys a configuration XML to your Maven repository. Then use an import to allow you to change banned dependencies without making changes to each individual project. Just like with the version notation in the includes and excludes elements, your import artifact element supports a version range. This way the latest banned dependencies can be side-loaded into all projects. This means previously functioning builds may eventually start failing. That is by design in this scenario.

The import elements supports multiple url or artifact declarations. All imported and directly specified include specifications are processed before all exclude specifications. You cannot change an include when importing, but you can add new ones, that may cover more versions; and you can exclude versions that may have been included by the import.

The excludes element is a way to provide project-by-project exceptions to imported banned artifacts where warranted.