Support for other languages inside the Scala DSL routes is delivered through traits. The org.apache.camel.scala.dsl.languages package currently offers traits to support XPath. To use any given language, you can mix-in the trait when creating your RouteBuilder.
With the XPath trait, you have an additional method available on an Exchange to do XPath queries against the message. Just look at this Splitter example, where the xpath method is used in a Exchange ⇒ Any* function literal
With the org.apache.camel.scala.dsl.languages.JXPath trait, you can an additional jxpath method on the Exchange. In the Recipient List example below, JXPath is used for getting the next endpoint's name out of the message body.