Maven is a software/dependency management tool for Java - it can be used to pull in dependencies and build a jar from a bunch of source
By default, the jar won't have dependencies rolled into it. Sometimes though, you want the overhead of the bigger jar.
mvn assembly:assembly -DdescriptorId=jar-with-dependencies
mvn assembly:assembly -DdescriptorId=jar-with-dependencies java -cp target/exampletest-1.0-SNAPSHOT-jar-with-dependencies.jar com.example.exampleorg.ExampleTestApp