准备工作：Download Java SE Development Kit 11.x.x x64 RPM Package

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[ponfey@ubuntu-desktop packages]# sudo mkdir -p /usr/local/jdk # 创建目录
[ponfey@ubuntu-desktop packages]# sudo tar zxvf jdk-11.0.15.1_linux-x64_bin.tar.gz -C /usr/local/jdk/ # 解压jdk11到jdk目录
[ponfey@ubuntu-desktop packages]# sudo mv /usr/local/jdk/jdk-11.0.15.1 /usr/local/jdk/jdk11

[ponfey@ubuntu-desktop ~]# sudo update-alternatives --install /usr/bin/java java /usr/local/jdk/jdk11/bin/java 100 # 添加 java 到 update-alternatives 进行管理
[ponfey@ubuntu-desktop ~]# sudo update-alternatives --config java # 切换java版本