public void download(WlCatalog wlCatalog,HttpServletRequest request,HttpServletResponse response){
String path=request.getSession().getServletContext().getRealPath("/");
String preff=path.split("/")[0];
WlCatalog wc = wlCatalogService.get(wlCatalog.getId());
String pic=wc.getInfo();
//String picName=pic.split("\\.")[1];//从数据库获取文件名称,自己拼接字符串
String ss=preff+"userfiles\\1\\files\\wl\\info\\a.png";
FileUtils.downFile(new File(ss),request,response);
}
http://blog.csdn.net/h3243212/article/details/50819218
http://blog.csdn.net/jacksonzhou88/article/details/62508188