下载并配置环境变量

[root@openeuler ~]# wget https://download.oracle.com/java/18/archive/jdk-18.0.2.1_linux-x64_bin.tar.gz
[root@openeuler ~]# tar zxvf jdk-18.0.2.1_linux-x64_bin.tar.gz -C /usr/local/
[root@openeuler ~]# vim /etc/profile
# 新加以下两行环境变量
export JAVA_HOME=/usr/local/jdk-18.0.2.1
export PATH=$JAVA_HOME/bin:$PATH
[root@openeuler ~]# source /etc/profile

验证

[root@openeuler ~]# java -version
java version "18.0.2.1" 2022-08-18
Java(TM) SE Runtime Environment (build 18.0.2.1+1-1)
Java HotSpot(TM) 64-Bit Server VM (build 18.0.2.1+1-1, mixed mode, sharing)
[root@openeuler ~]# javac -version
javac 18.0.2.1

测试

[root@openeuler ~]# cat hello.java 
public class hello {
        public static void main(String[] args) {
                System.out.println("Hello World");
        }
}
[root@openeuler ~]# javac hello.java 
[root@openeuler ~]# ls
hello.class  hello.java  jdk-18.0.2.1_linux-x64_bin.tar.gz
[root@openeuler ~]# java hello 
Hello World