mac查看jdk版本

卸载步骤
输入
sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -fr /Library/PreferencesPanes/JavaControlPanel.prefpane

查找当前版本
输入：ls /Library/Java/JavaVirtualMachines/
输出：jdk-9.0.1.jdk

sudo rm -rf /Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk