jetty-env.scala

// jetty6 imports 
import org.mortbay.jetty.webapp.{WebAppClassLoader, WebAppContext, WebInfConfiguration, Configuration, FragmentConfiguration, JettyWebXmlConfiguration, TagLibConfiguration, WebXmlConfiguration}
import org.mortbay.xml.XmlConfiguration
import org.mortbay.jetty.plus.webapp.{EnvConfiguration, Configuration=>PlusConfiguration}

// jetty7 imports 
import org.eclipse.jetty.webapp.{WebAppClassLoader, WebAppContext, WebInfConfiguration, Configuration, FragmentConfiguration, JettyWebXmlConfiguration, TagLibConfiguration, WebXmlConfiguration}
import org.eclipse.xml.XmlConfiguration
import org.eclipse.jetty.plus.webapp.{EnvConfiguration, Configuration=>PlusConfiguration}

// ...

val webapp = new WebAppContext(war.absolutePath, contextPath)

// ...

val envConfig = new EnvConfiguration
envConfig.setJettyEnvXml(jettyEnvFile.toURL)
val confArray : Array[Configuration] = Array(
	new WebInfConfiguration, 
	new WebXmlConfiguration,  
	envConfig, 
	new PlusConfiguration, 
	new JettyWebXmlConfiguration, 
	new TagLibConfiguration
)
webapp.setConfigurations(confArray)

MyProject.scala

class MyProject(info: ProjectInfo) extends DefaultWebProject(info){
	<!-- Your dependencies here -->
	val jetty7WebApp = "org.eclipse.jetty" % "jetty-webapp" % "7.0.2.RC0" % "test"
	val jetty7Server = "org.eclipse.jetty" % "jetty-server" % "7.0.2.RC0" % "test"
	val jetty7Plus = "org.eclipse.jetty" % "jetty-plus" % "7.0.2.RC0" % "test"

	<!-- Path to jetty-env.xml -->
	override def jettyEnvXml = Some( 
		(sourcePath / "main" / "jetty" / "jetty-env.xml").asFile
	)
}