How to find out why a jar was included by Maven?

It looks like the pattern passed to -Dincludes is incorrect.

From the documentation of Maven Dependency Plugin, the syntax of -Dincludes is defined by StrictPatternIncludesArtifactFilter. From the javadoc of AbstractStrictPatternArtifactFilter from which this is subclassed,

The artifact pattern syntax is of the form:

[groupId]:[artifactId]:[type]:[version]

Where each pattern segment is optional and supports full and partial * wildcards. An empty pattern segment is treated as an implicit wildcard.

For example, org.apache.* would match all artifacts whose group id started with org.apache., and :::*-SNAPSHOT would match all snapshot artifacts.

Maybe you should run mvn dependency:tree without -Dincludes and see if it shows up the spring 2.0 related dependency. Alternately, specify the appropriate pattern for -Dincludes.

The format you are searching for is wrong. Try this:

mvn dependency:tree -Dverbose -Dincludes=:spring*::

(Searches for any artifact with a groupId that starts with spring)

Or this:

mvn dependency:tree -Dverbose -Dincludes=org.springframework

(Searches for any artifact with artifactId org.springframework)

Why not use intellij and easy fix it.Open your pom.xml, right-click (invoke context menu) and choose UML > show dependencies (assumin you have UML plugin enabled). Idea will mark all duplicate dependency and you can use ALT+Enter combo to exclude dependencies. @see also:http://blogs.jetbrains.com/idea/2010/05/maven-dependencies-diagram/