在三大框架hibernate,struts2,spring中，实现文件的上传和下载。-In the three frameworks, file upload and download.

文件上传说白了就是利用form表单request域中上传数据，后台到Action中解析request域进行文件获取和文件类型以及后缀解析，过程比较繁琐，不过这些公共的繁琐步骤是struts框架已经为我们做好了，只需要按照其规则进行页面绘制和后台属性注入即可。(Upload file upload namely using form form request field data, the background to the Action of parsing the request domain

Apache、struts1、struts2文件上传下载的3种方式(3 ways of uploading and downloading Apache, struts1 and Struts2 files)

Struts2图片文件上传，判断图片格式和图片大小(Struts2 image file upload to determine the picture format and size of the picture)