1 安装python-software-properties

sudo apt-get install python-software-properties
sudo apt-get install software-properties-common

2 添加ppa

sudo add-apt-repository ppa:webupd8team/java

3 更新系统

sudo apt-get update

4 安装Java 1.8

sudo apt-get install oracle-java8-installer

5 验证是否安装成功

java -version

会显示： 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)