升级mac的java版本

#这应该是系统自带java环境，默认/usr/bin/java 指向这里 
/System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java   

＃这应该是浏览器下的java环境，oracle官方dmg貌似只更新这里
/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents

＃作为解决方案，可以下载oracle java的tar包，解压到这个目录下
/Library/Java/JavaVirtualMachines

＃设置bashrc文件，最终如下
[Luke@192 Versions]$ tail -n 4 /etc/bashrc_Apple_Terminal 

JAVA_HOME="/Library/Java/JavaVirtualMachines/jre1.8.0_74.jre/Contents/Home/"
CLASSPATH="$JAVA_HOME/lib"
PATH=.:$JAVA_HOME/bin:$PATH
[Luke@192 Versions]$ java -version
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode)
[Luke@192 Versions]$