(Although the output may change in the future as new Java versions are promoted to LTS status, or the current LTS version receives updates.) OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2, mixed mode)

OpenJDK Runtime Environment (build 11.0.11+9-Ubuntu-0ubuntu2) It should output the following: openjdk version '11.0.11' We can check if OpenJDK JRE was properly installed by running: java -version To install the OpenJDK JRE, we run: sudo apt install default-jre (Alternatively, you may opt to use a specific Java version, using for example the openjdk-11-jre package as updates are released for that version of the Java Virtual Machine, that packages will be updated, allowing you to stick to the latest and greatest update of one specific version of the Java language.) The default-jre is an excellent choice for most situations, thanks to the outstanding track of backwards compatibility of the Java Virtual Machine. Ubuntu offers the default-jre package, which is regularly updated to ship the latest version of the current OpenJDK JRE in Long Term Support (LTS).

Moreover, the non LTS versions of Java are bringing a steady stream of innovation into the language, and also see some adoption. Nowadays, Java 11 is the current Long Term Support (LTS) version, but Java 8 is still widely used. With new versions of Java released every 6 months, there are multiple versions available for use.

Apt install java