MAC 系统安装java并配置环境变量

/usr/libexec/java_home -V

cd ~

touch .bash_profile

vi .bash_profile

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home #jdk安装路径  
export PATH=$JAVA_HOME/bin:$PATH 
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

source .bash_profile

java -version