Is there a simple way to remove unused dependencies from a maven pom.xml?

Question

I have a large Maven project with numerous modules and pom.xmls. and the project has changed that much that I'm sure the pom's must have some unnecessary dependencies in them. does anyone know if there is a command you can run to remove any pointless dependencies from a pom?

Answer 1

Have you looked at the Maven Dependency Plugin ? That won't remove stuff for you but has tools to allow you to do the analysis yourself. I'm thinking particularly of

mvn dependency:tree

Answer 2

The Maven Dependency Plugin will help, especially the dependency:analyze goal:

dependency:analyze analyzes the dependencies of this project and determines which are: used and declared; used and undeclared; unused and declared.

Another thing that might help to do some cleanup is the Dependency Convergence report from the Maven Project Info Reports Plugin.

Answer 3

As others have said, you can use the dependency:analyze goal to find which dependencies are used and declared, used and undeclared, or unused and declared. You may also find dependency:analyze-dep-mgt useful to look for mismatches in your dependencyManagement section.

You can simply remove unwanted direct dependencies from your POM, but if they are introduced by third-party jars, you can use the <exclusions> tags in a dependency to exclude the third-party jars (see the section titled Dependency Exclusions for details and some discussion). Here is an example excluding commons-logging from the Spring dependency:

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring</artifactId>
  <version>2.5.5</version>
  <exclusions>
    <exclusion>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
    </exclusion>
  </exclusions> 
</dependency>