修改系统环境变量

vi /etc/profile

export JAVA_HOME=/opt/dev/jdk/jdk1.7.0_67
export PATH=$PATH:$JAVA_HOME/bin

修改用户环境变量

vi /root/.bash_profile
vi /home/user/.bash_profile
vi ~/.bash_profile

export JAVA_HOME=/opt/dev/jdk/jdk1.7.0_67
export PATH=$PATH:$JAVA_HOME/bin