===== Install Java Runtime Environment (JRE) on Linux =====

This page is a HOWTO for installing OpenJDK Java Runtime Envirobment (JRE) on Linux for use with the Crossfire [[jxclient|JXClient]] or the map editor, [[gridarta|Gridarta]] for Crossfire.

==== Debian, Linux Mint, Ubuntu ====

Run the following instructions for installing JRE on Debian, Linux Mint and Ubuntu.

Note that instructions also includes or applies to all the different Ubuntu flavours including:
  * Kubuntu
  * Lubuntu
  * Ubuntu Budgie
  * Ubuntu Mate
  * Xubuntu 

And also to the different Linux Mint spins including:
  * Cinnamon
  * KDE
  * LMDE
  * MATE
  * Xfce

To install this version, first update the package index:

  sudo apt update

Next, check if Java is already installed:

  java -version

If Java is not currently installed, you’ll see the following output:

  Output
  Command 'java' not found, but can be installed with:
  apt install default-jre
  apt install openjdk-11-jre-headless
  apt install openjdk-8-jre-headless

Execute the following command to install OpenJDK JRE:

  sudo apt install default-jre

This command will install the Java Runtime Environment (JRE). This will allow you to run almost all Java software.

Verify the installation with:

  java -version

You’ll see the following output:

  openjdk version "11.0.7-ea" 2020-04-14
  OpenJDK Runtime Environment (build 11.0.7-ea+9-post-Ubuntu-1ubuntu1)
  OpenJDK 64-Bit Server VM (build 11.0.7-ea+9-post-Ubuntu-1ubuntu1, mixed mode, sharing)