The Scala tour doesn’t directly cover the fact that you can access Java code from Scala.
In Scala, you have access to any Java library code, from the main libraries in
javax.* to any Java code in your classpath.
Here is a Servlet implemented in Scala that outputs a simple “hello world” in HTML (using XmlLiterals ).
My Thoughts on This Feature
This will be crucial for the adoption of Scala, especially in large enterprises that are slow to change their technical architecture.