JDK多版本环境配置

export JAVA_7_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk/Contents/Home
export JAVA_8_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_31.jdk/Contents/Home
export JAVA_HOME=$JAVA_7_HOME
alias jdk7='export JAVA_HOME=$JAVA_7_HOME'
alias jdk8='export JAVA_HOME=$JAVA_8_HOME'