Create Docker container with both Java and Node.js

I am not sure why I expected this to work:

 # Dockerfile    
 FROM node:6
 FROM java:8

but it doesn't really work, looks like the first command is ignored, and second command works.

Is there a straightforward way to install both Node.js and Java in a Docker container?

Ultimately the problem I am trying to solve is that I am getting an ENOENT error when running Selenium Webdriver -

[20:38:50] W/start - Selenium Standalone server encountered an error: Error: spawn java ENOENT

And right now I assume it's because Java is not installed in the container.

via Alexander Mills