1、筛选需要安装的jdk： yum search java | grep -i --color JDK

2、安装jdk：yum install java-1.8.0-openjdk-devel.x86_64

3、配置环境变量

  1. vi /etc/profile

  2. export JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64 export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar export PATH=$PATH:$JAVA_HOME/bin

4、让配置文件生效：source /etc/profile