jdk8的安装
sudo apt-get install openjdk-8-jdk
JDK7的安装
Ubuntu16.04的安装源已经默认没有openjdk7了,所以要自己手动添加仓库:
sudo add-apt-repository ppa:openjdk-r/ppa
sudo apt-get update
sudo apt-get install openjdk-7-jdk // OpenJdk 7安装:
大功告成!
update-java-alternatives -s java-7-oracle//切换到JDK7
update-java-alternatives -s java-8-oracle//切换到JDK8