You need java, maven (mvn) and git installed to be able to build the vectorgraphics library.
git clone git@github.com:freehep/freehep-vectorgraphics.git
cd freehep-vectorgraphics
mvn clean install
To run the example:
java -jar freehep-graphics2d-export-example/target/freehep-graphics2d-export-example-2.3.jar