在MAC上查找和设置$JAVA_HOME

1. 可以使用工具命令“/usr/libexec/java_home”来定位JAVA_HOME：

   定位JAVA：

   /usr/libexec/java_home -V Matching Java Virtual Machines (1): 1.8.0_25, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home

    

   另外可以使用-V选项列出所有版本的JAVA_HOME：

   $ /usr/libexec/java_home -V

   Matching Java Virtual Machines (3): 1.7.0_45, x86_64: "Java SE 7" /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home 1.6.0_65-b14-462, x86_64: "Java SE 6" /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home 1.6.0_65-b14-462, i386: "Java SE 6" /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home

    

   配置JAVA_HOME：

   $ cat ~/.profile

   JAVA_HOME=`/usr/libexec/java_home`

   export JAVA_HOME

   $ echo $JAVA_HOME /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home

   $ source ~/.profile $java

    

   JAVA_HOME=$(/usr/libexec/java_home -v 1.7)

    

   export JAVA_HOME