From charlesreid1

Installing Java requires some consideration: it is not an open source product. It is covered under a commercial license and is wholly owned by Oracle.

Installing

Mac

Java offers a binary installation of the JDK version 8 on the Mac as a dmg file, which executes a binary installer. This gives you access to the JVM, Java compiler, and various other developer tools like HPROF.

Linux

You have two options: one is to dirty your system by installing Sun's Oracle's copy of Java onto your system. The other is to get OpenJDK, available through aptitude.

$ apt-get install open-jdk-8-jdk

Windows

Double click the .exe and check the boxes and click Next Next Next Next Next Next Install