ubuntu 安装java8

安装ppa

#删除
sudo apt-get purge openjdk*

#安装software-properties-common
apt install software-properties-common

#安装webupd
add-apt-repository ppa:webupd8team/java   

#更新源
sudo apt-get update

#安装oracle-java-installer
sudo apt-get install oracle-java8-installer

#设置系统默认jdk
sudo update-java-alternatives -s java-8-oracle

#检测
java -version

javac -version