https://my.oschina.net/yongqingfan/blog/535749
http://www.blogjava.net/BearRui/archive/2010/05/19/flush_chunk_encoding.html
http://www.cnblogs.com/hoojo/p/longPolling_comet_jquery_iframe_ajax.html
javaweb 长连接
原文：http://www.cnblogs.com/yingsong/p/5939426.html