ubuntu 各种安装

jdk :
https://www.digitalocean.com/community/tutorials/how-to-install-java-on-ubuntu-with-apt-get

mysql:
https://help.ubuntu.com/12.04/serverguide/mysql.html

mongodb:
http://askubuntu.com/questions/147135/how-can-i-uninstall-mongodb-and-reinstall-the-latest-version