Ajax图片上传：前后端完整代码详解

Action:

 public void importLogo(ActionMapping mapping, ActionForm form,  
            HttpServletRequest request, HttpServletResponse response, String logoPath)  
            throws Exception {  
  SpInfoForm spInfoForm = (SpInfoForm)form;  
        FormFile logoFile = spInfoForm.getLogoFile(); 
        if(logoFile.getFileSize()>1048576){
         response.getWriter().print("上传的图片不能超过1M");
         return;
        }
        System.out.println(logoFile.getFileSize());
//         String dir = "F:/images/";//上传至本地指定路径，没有则创建  
        String dir = request.getSession().getServletContext().getRealPath("/")+"web/logoPictures/";//上传至服务器  
//         String dir =logoPath;
        if(logoFile != null){           
//          FileOutputStream fos = new FileOutputStream("c:/"+myFile.getFileName());  
            System.out.println(logoFile.getFileName());  
            File uploadFile = new File(dir);   //指定上传文件的位置  
//             String path = uploadFile.getAbsolutePath();   //绝对路径  
            System.out.println("Path:"+dir);  
            if (!uploadFile.exists() || uploadFile == null) {  //判断指定路径dir是否存在，不存在则创建路径  
                 uploadFile.mkdirs();  
            }  
            FileOutputStream fos = new FileOutputStream(dir+logoFile.getFileName());  
            fos.write(logoFile.getFileData());  
            fos.flush();  
            fos.close();  
            response.getWriter().print(dir+logoFile.getFileName());
        }