gcj-4.9-jre-headless software package provides Java runtime environment using GIJ/Classpath (headless version), you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gcj-4.9-jre-headless
gcj-4.9-jre-headless is installed in your system.
Make ensure the gcj-4.9-jre-headless package were installed using the commands given below,
$ sudo dpkg-query -l | grep gcj-4.9-jre-headless *
You will get with gcj-4.9-jre-headless package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Java |
| Package | gcj-4.9-jre-headless |
| Version | 4.9.3-13ubuntu2 |
| Description | Java runtime environment using GIJ/Classpath (headless version) |
| Sub Section | Java |