方法一：官网下载jdk1.8安装包
①cd /opt/java
②tar -zxf jdk-8u301-linux-x64.tar.gz
③解压后配置环境变量(普通用户)
vim .bash_profile
export JAVA_HOME=/opt/java/jdk1.8.0_181
export PATH=𝐽𝐴𝑉𝐴𝐻𝑂𝑀𝐸/𝑏𝑖𝑛:JAVAHOME/bin:PATH
export CLASSPATH=.:𝐽𝐴𝑉𝐴𝐻𝑂𝑀𝐸/𝑙𝑖𝑏/𝑑𝑡.𝑗𝑎𝑟:JAVAHOME/lib/dt.jar:JAVA_HOME/lib
④验证：java -version
[majd@crm-yy-test ~]$ java -version
java version “1.8.0_301”
Java™ SE Runtime Environment (build 1.8.0_301-b09)
Java HotSpot™ 64-Bit Server VM (build 25.301-b09, mixed mode)
方法二：yum安装
①yum搜索jdk安装包
yum search java | grep jdk
②下载jdk1.8
yum install java-1.8.0-openjdk
下载后的默认路径为/usr/lib/jvm
③配置环境变量(同上)
④验证
方法三：rpm安装
①下载rpm安装包
②安装rpm包
rpm -ivh jdk-8u181-linux-x64.rpm…
③配置环境变量
④验证
