查询 : yum search java|grep jdk rpm -qa | grep jdk
安装 : yum -y install java-1.8.0-openjdk*
默认位置 : /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64
vi /etc/profile :
JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64
CLASS_PATH=.
PATH=$PATH:$JAVA_HOME/bin\
export JAVA_HOME CLASS_PATH PATH
测试 : java -version
javac
