1、檢視系統位數、系統核心

root@ubuntu02:/home# getconf LONG_BIT
64

root@ubuntu02:/home# hostnamectl
   Static hostname: ubuntu02
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 3c186d21e7094b71a8889a2d78350c4b
           Boot ID: cc8cf35b8ad54b68a5a2f07eb4042153
    Virtualization: vmware
  Operating System: Ubuntu 
 
20.04.3 LTS
            Kernel: Linux 5.11.0-38-generic
      Architecture: x86-64

2、檢視當前java環境

root@ubuntu02:~# java -version   //忽略提示，使用安裝包進行安裝

Command 'java' not found, but can be installed with:

apt install openjdk-11-jre-headless  # version 11.0.11+9-0ubuntu2~20.04, or
apt install default-jre              # version 2
 
:1.11-72
apt install openjdk-13-jre-headless  # version 13.0.7+5-0ubuntu1~20.04
apt install openjdk-16-jre-headless  # version 16.0.1+9-1~20.04
apt install openjdk-17-jre-headless  # version 17+35-1~20.04
apt install openjdk-8-jre-headless   # version 8u292-b10-0ubuntu1~20.04

3、官網下載最新java jdk安裝包

下載地址：https://www.oracle.com/java/technologies/downloads/#java8

root@ubuntu02:/home/software# wget https://download.oracle.com/otn/java/jdk/8u311-b11/4d5417147a92418ea8b615e228bb6935/jdk-8u311-linux-x64.tar.gz

root@ubuntu02:/home/software# tar -xzvf jdk-8u311-linux-x64.tar.gz

root@ubuntu02:/home/software# ls
jdk1.8.0_311  jdk-8u311-linux-x64.tar.gz

4、

root@ubuntu02:/home/software# mkdir -p /usr/lib/jdk
root@ubuntu02:/home/software# mv jdk1.8.0_311 /usr/lib/jdk