JDK版本从1.7升级到1.8

升级JDK

# Ubuntu
# add-apt-repository: command not found
# 查看Ubuntu版本
cat /etc/issue
# For Ubuntu 14.04 or 16.04 you need another package:
apt-get install software-properties-common
# If you are using an older release of Ubuntu, ie before 12.10, it is necessary to install the package python-software-properties
sudo apt-get install python-software-properties

add-apt-repository ppa:webupd8team/java
apt-get update
apt-get install oracle-java8-installer

# 切换到jdk8
sudo update-java-alternatives -s java-8-oracle

# 完成