JDK6、JDK7、JDK8三个版本的汇总地址：https://pan.baidu.com/s/1pKSYv8Z

安装

JDK6安装

JDK6下载地址

见网盘

安装完毕后确认版本

JavaForOSX2014-001.dmg contains Java for Mac OS X (1.6.0_65-b14-462).It will be installed to * /System/Library/Java * and /System/Library/Frameworks while Oracle Java is located at /Library/Java

>cd /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
>./bin/java -version
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)

JDK7安装

JDK7下载地址

安装完毕后确认版本

JDK7之后，安装目录比较规范化了，按着版本号在/Library/Java/JavaVirtualMachines/下自动建立子目录

/Library/Java/JavaVirtualMachines>ls -lrt
total 0
drwxr-xr-x  3 root  wheel  102 11  2 15:22 jdk1.7.0_67.jdk
drwxr-xr-x  3 root  wheel  102 11  3 14:58 jdk1.7.0_71.jdk
drwxr-xr-x  3 root  wheel  102  4  9 13:44 jdk1.8.0_40.jdk5

JDK8安装

安装和下载同JDK7 
每次安装完后，自动更新/usr/libexec/java_home

/Users/lcz>/usr/libexec/java_home 
/Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home

配置多JDK版本环境

修改profile文件

1.打开~/.bash_profile，没有的话创建 
vim ~/.bash_profile 
2.在文件中写入，保存、退出

export JAVA_6_HOME=/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
export JAVA_7_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_71.jdk/Contents/Home
export JAVA_8_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home

alias jdk6="export JAVA_HOME=$JAVA_6_HOME" #编辑一个命令jdk6，输入则转至jdk1.6
alias jdk7="export JAVA_HOME=$JAVA_7_HOME" #编辑一个命令jdk8，输入则转至jdk1.8
alias jdk8="export JAVA_HOME=$JAVA_8_HOME" #编辑一个命令jdk8，输入则转至jdk1.8

export JAVA_HOME=`/usr/libexec/java_home`  #最后安装的版本，这样当自动更新时，始终指向最新版本

验证

/Users/lcz>. .bash_profile
/Users/lcz>java -version
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.40-b25, mixed mode)
/Users/lcz>jdk6
/Users/lcz>java -version
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
/Users/lcz>jdk7 
/Users/lcz>java -version
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)

java_Mac安装多个JDK版本并设置环境变量