1、下载jdk11版本，上传解压到用户目录/home/javaeleven
    su javaeleven 切换到该用户下

    2、

    1. [javaeleven@bogon home]$ vim /home/javaeleven/.bashrc

    3、末尾添加

    1. export JAVA_HOME=/home/javaeleven/jdk-11.0.13
    2. export JAVA_BIN=$JAVA_HOME/bin
    3. export PATH=$JAVA_HOME/bin:$PATH
    4. export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

    4、保存退出编辑
    5、[javaeleven@bogon home]$ source .bashrc
    6、校验

    1. [javaeleven@bogon home]$ java -version
    2. java version "11.0.13" 2021-10-19 LTS
    3. Java(TM) SE Runtime Environment 18.9 (build 11.0.13+10-LTS-370)
    4. Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.13+10-LTS-370, mixed mode)

    切换用户 

    1. [jiqiu@bogon home]$ java -version
    2. java version "1.8.0_311"
    3. Java(TM) SE Runtime Environment (build 1.8.0_311-b11)
    4. Java HotSpot(TM) 64-Bit Server VM (build 25.311-b11, mixed mode)