=== Transitive Dependencies

:doctype: article
:revnumber: {project-version}

As every dependencies build its own dependency tree two dependencies can depend on the same artifact.
But they do not necessarily depend on the same version.
This can result to a classpath with two version of the same dependency.

==== Solution

To work around this problem we define every transitive dependency in the dependency management exactly once with a defined version.
To search for all dependencies this script can be used:

    mvn org.apache.maven.plugins:maven-dependency-plugin:2.10:resolve | grep '\[INFO\]    ' | cut -d':' -f1-4 | sort | uniq | cut -c11- | grep -v none | grep -v org.eclipse | sed -r 's/(.*):(.*):(.*):(.*)/      \<dependency\>\n        \<groupId\>\1\<\/groupId\>\n        \<artifactId>\2\<\/artifactId\>\n        \<version\>\4\<\/version\>\n      \<\/dependency\>/'

It prints out the dependencies as maven dependencies.
Before this script is used the transitive section in the org.eclipse.scout.rt/pom.xml at the end of the dependencyManagement section should be commented or removed.
So we get all dependencies in their intended version.

The output can be compared to the effective POM of org.eclipse.scout.rt/pom.xml (with commented out transitive dependencies).
Duplicates can be removed and the remaining purely transitive dependencies can be added to the transitive section.

Note: c3p0 is an optional transitive dependency from quartz not used in Scout and can be omitted.