Ubuntu 20.04 安装 JDK

如果你对 JDK 和 JRE 有什么误解或者之间有什么关系还不是非常熟悉的话，请自行脑补下。

简单来说就是 JDK 是 JRE 的增强版，含有更多的工具集和 API。

在 Java 开发的时候通常都需要要求安装 JDK。

安装命令

apt install default-jdk

安装命令非常简单，直接执行上面的命令就行了。

在安装的时候，我们遇到了下面的错误：

Err:1 http://security.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre-headless amd64 11.0.10+9-0ubuntu1~20.04
  404  Not Found [IP: 91.189.88.142 80]
Err:2 http://security.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jre amd64 11.0.10+9-0ubuntu1~20.04
  404  Not Found [IP: 91.189.88.142 80]
Err:3 http://security.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk-headless amd64 11.0.10+9-0ubuntu1~20.04
  404  Not Found [IP: 91.189.88.142 80]
Err:4 http://security.ubuntu.com/ubuntu focal-updates/main amd64 openjdk-11-jdk amd64 11.0.10+9-0ubuntu1~20.04
  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/o/openjdk-lts/openjdk-11-jre-headless_11.0.10+9-0ubuntu1~20.04_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/o/openjdk-lts/openjdk-11-jre_11.0.10+9-0ubuntu1~20.04_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/o/openjdk-lts/openjdk-11-jdk-headless_11.0.10+9-0ubuntu1~20.04_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/o/openjdk-lts/openjdk-11-jdk_11.0.10+9-0ubuntu1~20.04_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?