1.修改 /etc/profile 文件中的JAVA_HOME 为新的地址(配置环境变量)
vim /etc/profile
. . . . . .
export JAVA_HOME=/usr/local/jdk1.8.0_211
export JRE_HOME=/usr/local/jdk1.8.0_211/jre
export PATH=$PATH:/usr/local/jdk1.8.0_211/bin
export CLASSPATH=./:/usr/local/jdk1.8.0_211/lib:/usr/local/jdk1.8.0_211/jre/lib
2.执行以下命令
ln -s $JAVA_HOME/bin/java /usr/bin/java
ln -s $JAVA_HOME/bin/javac /usr/bin/javac
3.刚修改的环境变量生效
source /etc/profile
4.执行如下命令
[root@ceshi-1 ~]# java -version
java version "1.8.0_211"