//		 no jfreechart imports required (we'll find them programmatically)
import groovy.swing.SwingBuilder
import static javax.swing.WindowConstants.EXIT_ON_CLOSE

class MavenDependencyTest extends GroovyTestCase {

	void testSomething() {
		def classLoader = Thread.currentThread().contextClassLoader

//		 load jars and add to classpath
		def maven = MavenDependency.using(classLoader)
		maven.require(groupId:'jfree', artifactId:'jfreechart', version:'1.0.5')
		maven.require(groupId:'jfree', artifactId:'jcommon', version:'1.0.9')

//		 define used classes/instances programmatically
		def factoryClass     = classLoader.loadClass('org.jfree.chart.ChartFactory')
		def orientationClass = classLoader.loadClass('org.jfree.chart.plot.PlotOrientation')
		def dataset = classLoader.loadClass('org.jfree.data.category.DefaultCategoryDataset').newInstance()

//		 normal code below here
		dataset.addValue 150, "no.1", "Jan"
		dataset.addValue 210, "no.1", "Feb"
		dataset.addValue 390, "no.1", "Mar"
		dataset.addValue 300, "no.2", "Jan"
		dataset.addValue 400, "no.2", "Feb"
		dataset.addValue 200, "no.2", "Mar"

		def labels = ["Bugs", "Month", "Count"]
		def options = [true, true, true]
		def chart = factoryClass.createLineChart(*labels, dataset,
		        orientationClass.VERTICAL, *options)
		def swing = new SwingBuilder()
		def frame = swing.frame(title:'Groovy LineChart',
		        defaultCloseOperation:EXIT_ON_CLOSE) {
		    panel(id:'canvas') { rigidArea(width:400, height:400) }
		}
		frame.pack()
		frame.show()
		chart.draw(swing.canvas.graphics, swing.canvas.bounds)
	}

}

Maven 2 Ant Task - MavenDependencyTest Script

Groovy