[SOLVED] Maven transitive dependency - Commons Collection version 3 vs 4

Maven transitive dependency - Commons Collection version 3 vs 4

I have such configuration in pom.xml:

    <dependency>
        <groupId>commons-beanutils</groupId>
        <artifactId>commons-beanutils</artifactId>
        <version>1.9.4</version>
    </dependency>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-collections4</artifactId>
        <version>4.4</version>
    </dependency>

But unfortunately mvn dependency:tree shows me that commons-beanutils has dependency: commons-collections 3.x:

[INFO] +- commons-beanutils:commons-beanutils:jar:1.9.4:compile
[INFO] |  \- commons-collections:commons-collections:jar:3.2.2:compile
[INFO] +- org.apache.commons:commons-collections4:jar:4.4:compile

I don't want Common Collection 3 in my code but it's possible that someone uses a class from this library by mistake (instead of Common Collective 4, which is preferred version).

As you see in dependency tree - I can't exclude the Common Collection 3, because it is used (can occur java.lang.NoClassDefFoundError).

Question:

How to protect my code base against pollution of Commons Collection 3 API?

Solution

You can use the dependency:analyze-only

https://maven.apache.org/plugins/maven-dependency-plugin/analyze-only-mojo.html

to check whether you use undeclared dependencies, i.e. you use a transitive dependency without explicitly declaring it.

If you don't want this in your build, but just check it occasionally, you can use dependency:analyze from the command line.