一、卸載openjdk

1.查看java安裝軟件

[root@VM-20-14-centos ~]# rpm -qa|grep java
java-1.8.0-openjdk-1.8.0.312.b07-1.el8_4.x86_64
tzdata-java-2021e-1.el8.noarch
java-1.8.0-openjdk-headless-1.8.0.312.b07-1.el8_4.x86_64
javapackages-filesystem-5.3.0-1.module_el8.0.0+11+5b8c10bd.noarch

2.卸載openjdk

yum -y remove tzdata-java.noarch
或
yum -y remove *openjdk*

二、安裝oracle jdk8

1.下載jdk8

1）官網(wǎng)下載Linux環(huán)境下的jdk1.8
http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
賬號：youngliu102@163.com
密碼：Oracle@123

2）網(wǎng)盤下載
鏈接：https://pan.baidu.com/s/1Nv5sVVElLMw0h_KRdZ0Ktg
提取碼：2drg

2.創(chuàng)建文件目錄

mkdir /usr/local/java

3.上傳jdk包

官網(wǎng)下載jdk包，上傳到服務(wù)器/usr/local/java目錄

4.解壓

tar -vzxf jdk-8u311-linux-x64.tar.gz

5.設(shè)置環(huán)境變量

vim /etc/profile

末尾添加

export JAVA_HOME=/usr/local/java/jdk1.8.0_311
export JRE_HOME=${JAVA_HOME}/jre 
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib 
export PATH=${JAVA_HOME}/bin:$PATH

保存退出并刷新配置文件，執(zhí)行：

source /etc/profile

6.驗證是否安裝成功

[root@VM-20-14-centos ~]# java -version
java version "1.8.0_311"
Java(TM) SE Runtime Environment (build 1.8.0_311-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.311-b11, mixed mode)