原文：http://blog.csdn.net/coding_my_future/article/details/49927749
安装python-software-properties
$sudo apt-get install python-software-properties
$sudo apt-get install software-properties-common首先添加ppa
$ sudo add-apt-repository ppa:webupd8team/java然后更新系统
$ sudo apt-get update最后开始安装
$ sudo apt-get install oracle-java8-installer
$ java -version
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) Server VM (build 25.5-b02, mixed mode)java版本切换
sudo update-java-alternatives -s java-8-oracle