mac上卸载java

sudo rm -rf /Library/Java/JavaVirtualMachines/jdk-9.jdk 

sudo rm -fr /Library/Internet Plug-Ins/JavaAppletPlugin.plugin 

sudo rm -fr /Library/PreferencePanes/JavaControlPanel.prefPane 

sudo rm -fr ~/Library/Application Support/Oracle/Java 

根据java版本选择卸载，上面第一行是卸载java9