使用SmartUpload组件实现文件上传

publicclassUploadServletextendsHttpServlet {

    privatestaticfinallongserialVersionUID = 1L;

    protectedvoiddoPost(HttpServletRequest request,

           HttpServletResponse response) throwsServletException, IOException {

       // 对象输出声明

       response.setContentType("text/html;charset=utf-8");

       PrintWriter out = response.getWriter();

       // 准备上传的目录

       String path = this.getServletContext().getRealPath("photo");

       File fpath = new File(path);

       if (!fpath.exists()) {

           fpath.mkdir();

       }

       // 实例化组件

       SmartUploadsu = newSmartUpload("utf-8");

       // 初始化组件

       su.initialize(this.getServletConfig(), request, response);

       // 上传限制

       su.setMaxFileSize(50 * 1024); // 设置大小50K

       su.setAllowedFilesList("gif,png,jpg"); // 设置上传类型

       try {

           // 上传文件

           su.upload();

           // 获取上传的第一个文件

           SmartFile file = su.getFiles().getFile(0);

           // 判断是否有文件上传，没有选择文件则提示用户

           if (file.isMissing()) {

              out.println("<script>alert('请选择要上传的文件！');location.href='upload.jsp';</script>");

              return;

           }

           // 按照规则准备文件名按规则

           String fname = new Date().getTime()

                  + (newRandom().nextInt(900) + 100) + "."

                  + file.getFileExt();

           // 把文件从缓存区转移到指定目录中

           file.saveAs(path + "/" + fname);

           out.println("<script>alert('文件上传成功！');location.href='upload01.jsp';</script>");

       } catch (SecurityException e) {

           e.printStackTrace();

           // 违反上传限制的异常处理

           out.println("<script>alert('请选择合法的文件！');location.href='upload01.jsp';</script>");

       } catch (SmartUploadException e) {

           e.printStackTrace();

           out.println("<script>alert('文件上传失败！');location.href='upload01.jsp';</script>");

       }

    }

}