简单地运行:

sudo apt-get install default-jdk

如果你想安装Oracle JDK，你可以使用这个自动的脚本来完成所有的工作。

在作者的博客上有详细的使用说明。

安装Oracle的Java JDK要求您在开始安装之前接受Oracle许可证。这只需要一次。如果出于某种原因需要自动化安装，可以运行以下命令在没有用户交互的情况下进行安装，例如，这对于自动脚本很有用。

sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get update
echo debconf shared/accepted-oracle-license-v1-1 select true | sudo debconf-set-selections
echo debconf shared/accepted-oracle-license-v1-1 seen true | sudo debconf-set-selections
sudo apt-get -y install oracle-java8-installer
java -version

安装在ubuntu 18.04中

我的解决办法是，

$ sudo apt update

安装OpenJDK 8:

$ sudo apt install openjdk-8-jdk

通过运行以下命令来验证Java安装，该命令将打印Java版本:

$ java -version

输出应该是这样的:

输出:

openjdk version "1.8.0_191"
OpenJDK Runtime Environment (build 1.8.0_191-8u191-b12-2ubuntu0.18.04.1-b12)
OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode)

参考问Ubuntu问题如何设置OpenJDK的JAVA_HOME ?，

如何在Ubuntu (Linux)下安装Open JDK (Java开发工具包)?

Open Terminal from Application Dash or press Ctrl+Alt+T Update repository: sudo add-apt-repository ppa:openjdk-r/ppa # only Ubuntu 17.4 and earlier sudo apt update Optional: To search available distributions of openjdk, use the following command: apt search openjdk Install the appropriate version with the following command: sudo apt install openjdk-8-jdk sudo apt install openjdk-8-source #this is optional, the jdk source code For JAVA_HOME (Environment Variable) type command as shown below, in "Terminal" using your installation path... export JAVA_HOME=/usr/lib/jvm/java-8-openjdk (Note: /usr/lib/jvm/java-8-openjdk is symbolically used here just for demostration. You should use your path as per your installation.) For PATH (Environment Variable) type command as shown below, in Terminal: export PATH=$PATH:$JAVA_HOME/bin To check your installation: java -version

Install the appropriate version of OpenJDK JAVA_VERSION=8 sudo add-apt-repository -y ppa:openjdk-r/ppa sudo apt-get update sudo apt-get -qq install -y openjdk-$JAVA_VERSION-jdk Set Environment Variables in /etc/profile.d/jdk.sh JAVA_HOME=/usr/lib/jvm/java-$JAVA_VERSION-openjdk-amd64 echo "export JAVA_HOME=$JAVA_HOME" | sudo tee -a /etc/profile.d/jdk.sh echo "export J2SDKDIR=$JAVA_HOME" | sudo tee -a /etc/profile.d/jdk.sh echo "export J2REDIR=$JAVA_HOME/jre" | sudo tee -a /etc/profile.d/jdk.sh echo "export PATH=$PATH:$JAVA_HOME/bin:$J2REDIR/bin" | sudo tee -a /etc/profile.d/jdk.sh Check your installation /bin/bash /etc/profile.d/jdk.sh java -version echo $JAVA_HOME echo $J2REDIR echo $PATH