mv /etc/apt/sources.list /etc/apt/sources.list.bak
echo 'deb http://mirrors.163.com/debian/ jessie main non-free contrib' > /etc/apt/sources.list
echo 'deb http://mirrors.163.com/debian/ jessie-updates main non-free contrib' >> /etc/apt/sources.list
echo 'deb http://mirrors.163.com/debian-security/ jessie/updates main non-free contrib' >> /etc/apt/sources.list