Ubuntu 21.10下安装配置JDK17

        通过Multipass创建的虚拟机默认的jdk是OpenJDK 11，通过下面步骤我们把JDK换成Oracle JDK 17。

1、下载JDK17的Linux最新版本

wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.tar.gz

2、解压下载好的压缩包

tar -zxvf jdk-17_linux-x64_bin.tar.gz

3、把解压后的文件夹移动到/usr/local目录下

sudo mv jdk-17.0.3.1 /usr/local/

4、配置环境变量

sudo vi /etc/profile

5、按i进入编辑模式，并移动到文件末尾，添加以下配置

export JAVA_HOME=/usr/local/jdk-17.0.3.1
export CLASSPATH=.:$JAVA_HOME/lib
export PATH=.:$JAVA_HOME/bin:$JAVA_HOME/lib:$PATH

6、按Esc退出编辑模式，输入:wq保存文件

ubuntu@docker:~$ cat /etc/profile
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).
 
if [ "${PS1-}" ]; then
  if [ "${BASH-}" ] && [ "$BASH" != "/bin/sh" ]; then
    # The file bash.bashrc already sets the default PS1.
    # PS1='\h:\w\$ '
    if [ -f /etc/bash.bashrc ]; then
      . /etc/bash.bashrc
    fi
  else
    if [ "$(id -u)" -eq 0 ]; then
      PS1='# '
    else
      PS1='$ '
    fi
  fi
fi
 
if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi
 
export JAVA_HOME=/usr/local/jdk-17.0.3.1
export CLASSPATH=.:$JAVA_HOME/lib
export PATH=.:$JAVA_HOME/bin:$JAVA_HOME/lib:$PATH

7、配置生效

source /etc/profile

8、检查配置是否有效

ubuntu@docker:~$ java -version
java version "17.0.3.1" 2022-04-22 LTS
Java(TM) SE Runtime Environment (build 17.0.3.1+2-LTS-6)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.3.1+2-LTS-6, mixed mode, sharing)
ubuntu@docker:~$