GNU/Linux Mint Installing Java OpenJDK Guide
The linked Tutorials Show You Step-by-Step How to Install and Getting-Started with Oracle-Sun Java OpenJDK JRE/JDK on GNU+Linux Mint Desktops.
The OpenJDK (Open Java Development Kit) is a Free and Open Source Implementation of the Java Platform, Standard Edition (Java SE).
Oracle Java JDK/JRE Installation is based on the OpenJDK source code. In Addition, it contains Closed-Source Components.