从官网下载jdk1.8 https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
创建目录
mkdir /usr/local/java
tar zxf jdk-8u231-linux-x64.gz
配置环境变量 vi /etc/profile
export JAVA_HOME=/usr/local/java/jdk1.8.0_231
export JRE_HOME=/usr/local/java/jdk1.8.0_231/jre
export CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin
生效 source /etc/profile
java -version
java version "1.8.0_231"
Java(TM) SE Runtime Environment (build 1.8.0_231-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.231-b11, mixed mode)
centOS7 安装java
原文：https://www.cnblogs.com/zhuch-402/p/11845883.html
