Two maven versions required in pom.xml - what to do?

Question

I'm trying to build JavaOCR project with mvn clean install . There is used maven-enforcer-plugin in the pom.xml and there are two required Maven versions. (Or maybe I misunderstood something)

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-enforcer-plugin</artifactId>
    <version>1.4</version>
    <executions>
        <execution>
            <id>enforce-versions</id>
            <goals>
                <goal>enforce</goal>
            </goals>
            <configuration>
                <rules>
                    <requireMavenVersion>
                        <!--different rules for different issues-->
                        <!--3.3.x causes `java.lang.NoClassDefFoundError: org/eclipse/aether/spi/connector/Transfer$State` which is caused by certain maven versions, see https://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound for details-->
                        <version>(,3.3)</version>
                        <!--3.2.x causes `No implementation for org.eclipse.aether.connector.wagon.WagonConfigurator was bound.`-->
                        <version>(,3.2)</version>
                    </requireMavenVersion>
                </rules>
            </configuration>
        </execution>
    </executions>
</plugin>

Currently I have installed maven 3.3.3 and it throws the java.lang.NoClassDefFoundError error (same as described in the comment in pom.xml ), so I cannot build it.

My question is what version should I use to build the project successfully? Is it possible to use two maven versions simultaneously?

Answer 1

According to Maven's Version Range Specification documentation, that's specifying a range, not a specific version. (,3.2) means anything less than version 3.2, so those two configurations are compatible: for example, use version 3.1.

This is reinforced by the comments in the pom file, which say that versions 3.2.x and 3.3.x cause errors, so don't use them.

See also

• Version Range Specification