wget https://download.oracle.com/java/21/latest/jdk-21_linux-x64_bin.tar.gz
tar -zxvf jdk-21_linux-x64_bin.tar.gz

创建jdk安装目录

mkdir /usr/local/java/

将解压出来的jdk安装包移动到新建的jdk安装目录下

mv ./jdk-21.0.5/ /usr/local/java/

将环境变量配置添加到 /etc/profile 文件中

vi /etc/profile

export JAVA_HOME=/usr/local/java/jdk-21.0.5/
export JRE_HOME=$JAVA_HOME/jre
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

加载配置文件

source /etc/profile