学习博客

博客1：http://blog.csdn.net/longyi_java/article/category/767793

博客2(开篇-网络连接判断)：http://blog.csdn.net/walker02/article/details/7348878

http://www.cnblogs.com/lxblog/category/444487.html

http://androiddada.iteye.com/blog/1280946