有用的连接
http://www.bitscn.com/os/linux/201012/192506.html
http://www.bitscn.com/os/linux/201105/193120.html
http://www.bitscn.com/os/linux/201105/193164.html
http://www.bitscn.com/os/linux/201011/192365.html
http://www.bitscn.com/os/linux/201012/192404.html
http://svn.apache.org/viewvc/logging/log4j/trunk/
