# apt install java-runtime-headless
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package java-runtime-headless is a virtual package provided by:
  openjdk-9-jre-headless 9~b94-1
  openjdk-8-jre-headless 8u72-b05-6
  openjdk-6-jre-headless 6b37-1.13.9-1
  gcj-5-jre-headless 5.3.1-5ubuntu1
  gcj-4.8-jre-headless 4.8.5-3ubuntu3
  openjdk-7-jre-headless 7u91-2.6.3-3
  gcj-jre-headless 4:5.2.1-16ubuntu2
  gcj-4.9-jre-headless 4.9.3-9ubuntu1
  default-jre-headless 2:1.7-52.1
You should explicitly select one to install.

E: Package 'java-runtime-headless' has no installation candidate