关于springmvc跨域：
http://www.cnblogs.com/asfeixue/p/4363372.html
https://my.oschina.net/u/1421591/blog/529032
HTTP访问控制(CORS)
https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Access_control_CORS
http://twlidong.github.io/blog/2013/12/22/kua-yuan-zi-yuan-gong-xiang-cross-origin-resource-sharing-cors/