On your mac you can call the following command to show all installed Java virtual machines.
/usr/libexec/java_home --verbose
Output without any JVM installed
mymac$ /usr/libexec/java_home --verbose
Unable to find any JVMs matching version "(null)".
Matching Java Virtual Machines (0):
Default Java Virtual Machines (0):
No Java runtime present, try --request to install.
On my mac the output is:
mymac$ /usr/libexec/java_home --verbose
Matching Java Virtual Machines (5):
9.0.1, x86_64: "Java SE 9.0.1" /Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk/Contents/Home
9, x86_64: "Java SE 9" /Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home
1.8.0_144, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home
1.8.0_112, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_112.jdk/Contents/Home
1.8.0_111, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home
The total clean out
sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -fr /Library/PreferencePanes/JavaControlPanel.prefPane
sudo rm -fr ~/Library/Application\ Support/Oracle/Java
sudo rm -fr /Library/Java/JavaVirtualMachines/*
