C:\> setx JAVA_HOME "C:\Program Files\Java\jdk1.8.0_231"
C:\> setx PATH "%JAVA_HOME%;%JAVA_HOME%\bin;%JAVA_HOME%\lib;%PATH%;"
C:\> echo %JAVA_HOME%
C:\Program Files\Java\jdk1.8.0_231
you installed everything correctly.$ sudo apt update
$ sudo apt-get install openjdk-8-jdk
$ sudo update-alternatives --config java