1.查看yum源中是否有相关套件yum -y list java*
2.安装Java1.8
yum -y install java-1.8.0-openjdk-devel.x86_64
3.修改/etc/profile JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.181-3.b13.el7_5.x86_64 JRE_HOME=$JAVA_HOME/jre PATH=$PATH:$JAVA_HOME/bin CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar export JAVA_HOME export JRE_HOME export PATH export CLASSPATH PS：/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.181-3.b13.el7_5.x86_64注意此处路径
4.使环境变量生效
source /etc/profile
5.Java版本检查
java -version
