sudo cp -r jdk1.8.0_231 /usr/local/jdk1.8
查看已经安装的jdk版本,我这里安装了openjdk12,openjdk8和oriclejdk8
sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_231/bin/java 300
sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_231/bin/javac 300
sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8.0_231/bin/jar 300
sudo update-alternatives --config java
原文:https://www.cnblogs.com/zhouyu0-0/p/11741132.html