POI文件导出至EXCEL，并弹出下载框

相关参考帖子 ：

【1】http://www.tuicool.com/articles/MnqeUr

【2】http://www.oschina.net/question/253469_51638?fromerr=KAk0NKvi

【3】http://blog.csdn.net/evangel_z/article/details/7332535

报错参考：

Resource interpreted as Document but transferred with MIME type application/

将类型改为change the content-type: text/html

由response.setContentType("application/octet-stream")改为       

response.setContentType("text/html");