单例模式VS静态方法VS每次new对象

http://blog.youkuaiyun.com/johnny901114/article/details/11969015 

http://javarevisited.blogspot.com/2013/03/difference-between-singleton-pattern-vs-static-class-java.html

http://javarevisited.blogspot.com/2011/03/10-interview-questions-on-singleton.html

http://blog.youkuaiyun.com/zhangjg_blog/article/details/17089623

http://www.eoeandroid.com/thread-311014-1-1.html?_dsign=70d33822

http://www.cnblogs.com/Cyning/p/3663044.html

http://www.cnblogs.com/seesea125/archive/2012/04/05/2433463.html