mac设置java环境变量， 使用oh-my-zsh

参考：http://www.mkyong.com/java/how-to-set-java_home-environment-variable-on-mac-os-x/

如果用bash，修改~/.bash_profile 或 ~/.profile；

如果用zsh，修改～/.zshrc

修改这些文件之后，重修打开terminal，配置不会丢

首先确保已经安装了jdk：

## check the present running java
which java

## check java version
java -version

以zsh为例：

 ## check all the available jdk
 /usr/libexec/java_home -V

 ## check the top jdk
 /usr/libexec/java_home

 ## check some jdk (eg. version 1.7)
 /usr/libexec/java_home -v 1.7

 ## edit .zshrc to set java_home variable
 vim ~/.zshrc

 ## add the following line into the file
 export JAVA_HOME=$(/usr/libexec/java_home)

 ## you can also use the following line to set the variable, which is not recommended, only for older mac os.
 ## export JAVA_HOME=/System/Library/Java/JavaVirtualMachines/1.6..jdk/Contents/Home

 ##let the configuration in .zshrc take effect
 source ~/.zshrc

 ## check if configure succeed
 echo $JAVA_HOME