百度经验：https://jingyan.baidu.com/article/908080221f3cfefd91c80fbf.html
JDK下载网址：http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
Mac--安装JDK
原文：https://www.cnblogs.com/kaixinyufeng/p/9019423.html
