1、查看已安装版本

[root@localhost bin]# rpm -qa|grep jdk
jdk-1.7.0_80-fcs.x86_64
jdk1.8.0_121-1.8.0_121-fcs.x86_64

 

2、删除已安装版本

[root@localhost bin]# yum -y remove jdk1.8.0_121-1.8.0_121-fcs.x86_64

 

 3、解压配置环境变量并检查

[root@localhost opt]# tar -zxvf jdk-8u281-linux-x64.tar.gz -C /opt/java/
[root@localhost jdk1.8.0_281]# export JAVA_HOME=/opt/java/jdk1.8.0_281
[root@localhost jdk1.8.0_281]# export JRE_HOME=$JAVA_HOME/jre
[root@localhost jdk1.8.0_281]# export CLASSPATH=.:$CLASSPATH:$JAVA_HOME/lib:$JRE_HOME/lib
[root@localhost jdk1.8.0_281]# export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin
[root@localhost jdk1.8.0_281]# source /etc/profile
[root@localhost jdk1.8.0_281]# java -version
java version "1.8.0_281"
Java(TM) SE Runtime Environment (build 1.8.0_281-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.281-b09, mixed mode)
[root@localhost jdk1.8.0_281]#