Here is how to setup JAVA_HOME and PATH environment variables for a single user or all users on Fedora Linux system.

Setting JAVA_HOME and PATH for a single user
add following lines in the end of  ~/.bash_profile

export JAVA_HOME=/opt/jdkx.x.x_xx
export PATH=$PATH:$JAVA_HOME/bin

Setting JAVA_HOME and PATH for all users
add following lines in the end of  /etc/profile

export JAVA_HOME=/opt/jdkx.x.x_xx
export PATH=$PATH:$JAVA_HOME/bin

Apply the change

source /etc/profile

Setting JAVA_HOME for a single user and all users