By default, Ubuntu does not come with Java (or the Java Runtime Environment, JRE) installed. However, you may need it for some programs or games like Minecraft. … However, before installing Java, let’s make sure all the packages are up to date.

How do I know if Java is installed on Ubuntu?

To check the Java version on Linux Ubuntu/Debian/CentOS:

1. Open a terminal window.
2. Run the following command: java -version.
3. The output should display the version of the Java package installed on your system. In the example below, OpenJDK version 11 is installed.

Is Java pre installed on Linux?

There are many Linux distributions available and many of them come with one or more Java platform/s pre-installed. In the vast majority of the cases the Java platform which comes pre-installed on a Linux machine is not the official Oracle Java, but another one such as OpenJKD or IBM Java.