Ubuntu Linux

Since Oracle Java 11 can't be directly downloaded from Oracle any more, the installer no longer works, so I created a new installer that requires the user to create an Oracle account, download the Oracle Java 11 .tar.gz archive (the same version as the installer), and place the archive in /var/cache/oracle-jdk11-installer-local/. After this, you can install the oracle-java11-installer-local package, and it will set up Oracle Java 11 for you on Ubuntu or Linux Mint.

This article on Linux Uprising explains how to use the new installer for Oracle Java 11, to install the JDK using a local .tar.gz that you've manually downloaded from the Oracle website, using your Oracle signin.