Download the JDK package from Oracle.com
Go to oracle.com, follow the download link, select Java Downloads, then click Java SE. The latest version of JDK download should clearly visible. Follow the link and look for the tar.gz package for Linux64 system, for example jdk-8u73-linux-x64.tar.gz, about 173 MB, and save the tarball file to an appropriate folder where the JDK files are to be installed.
Unpack the files with tar -zxvf jdk-8u45-linux-x64.tar.gz command.
Setting PATH and JAVA_HOME environment variables
In order to allow executing java commands from any directory and let other programs that uses Java SDK, PATH and JAVA_HOME variables must be set up.
Fatdog64 uses /etc/profile for environmental variables.
Edit the profile to include the Java paths in PATH variable, define and export JAVA_HOME.
Run command 'which java', 'which javac', 'java -version' and 'javac -version' to verify that java has been installed and referred to properly.
Follow instructions from oracle.com or google documents on line to resolve various issues.