转自：http://www.2cto.com/kf/201210/161016.html
http://www.blogjava.net/athrunwang/archive/2012/02/20/370315.html
http://abeetle.iteye.com/blog/233896
http://hi.baidu.com/a889275/item/8721ead2973c711ed90e4416
jakarta commons stringutils chom google/baidu