转载自:http://blog.csdn.net/sunjing21/article/details/4779321
实现主要功能:
- 页面提供一个上传图片的input file选择框,用于上传某一类型的数张图片
- 每次选择完本地图片后,图片便异步存储到后台的文件夹中;
- 并将路径信息存储到数据库中;
- 页面上显示此图的缩略图,并在旁边显示一个删除标记,当点击时,将此图片从页面、数据库、后台的文件夹中删除
- input file选择框清空,再点击用于上传下一张图片;
JSP页面编写如下:
<div> <form action="uploadWaiguanImage.do" id="waiguan_form" name="waiguan_form" enctype="multipart/form-data" method="post" target="waiguan_hidden_frame"> <span> <label>外观图</label> <img src="images/addImage.JPG"> <input type="file" id="waiguan_add" name="waiguan_add"/> </span> <iframe name="waiguan_hidden_frame" id="waiguan_hidden_frame" style="display:none"></iframe> <c:forEach var="x" begin="1" end="3" step="1"> <span> <img id="waiguan_image${x }" style="visibility:hidden" src="" width="100" alt="外观图${x }"/> <img id="waiguan_delete_image${x }" style="visibility:hidden;cursor: pointer" src="images/deleteImage.JPG"/> </span> </c:forEach> </form> </div>
让form的target值为iframe,当form提交的时候,是异步iframe进行提交,不会影响页面的其他部分。
c:forEach部分是首先隐藏了上传后显示的图片标签和删除标签(这里最大可以上传三张)
相应的JS代码:采用的是JQuery写的,不过写的很啰嗦,有点像是原始JS操作
/** * 页面加载时完成操作 */ $(document).ready(function() { // 设置上传外观图 $("#waiguan_add").bind("change", function() { submitImage("waiguan", 3); }); } /** * 上传图片 * * @param {} * para_name 图片所属属性名 * @param {} * number 此类图片的总数量 */ function submitImage(para_name, number) { var para_form = para_name + "_form"; var para_image = para_name + "_image"; // alert(para_image); for (var i = 1; i <= number; i++) { var srcValue = $("#" + para_image + i).attr("src"); // alert(srcValue); // alert(srcValue.length); if (srcValue == "" || srcValue.length == 0) { // alert("break"); break; } } if (i > number) { alert("已超过了此类图的上传最大限"); // 重置上传按钮,使之为空 resetUploadBotton(para_name + "_add"); } else { $("#" + para_form).submit(); } } /** * iframe上传外观图片的返回操作 * * @param {} * msg 返回的图片所在地址 */ function callbackWaiguan(msg) { if (msg != "error") { for (var i = 1; i <= 3; i++) { var srcValue = $("#waiguan_image" + i).attr("src"); // alert(srcValue); if (srcValue == "" || srcValue.length == 0) { $("#waiguan_image" + i).attr("src", msg); $("#waiguan_image" + i).css("visibility", "visible"); $("#waiguan_delete_image" + i).css("visibility", "visible"); $("#waiguan_delete_image" + i).click(function() { deleteImage("waiguan", i); }); break; } } } else { alert("上传图片失败,后台程序出现问题!"); } // 重置上传按钮,使之为空 resetUploadBotton("waiguan_add"); } /** * 删除某个图片时的异步操作 * * @param {} * para_name * @param {} * number */ function deleteImage(para_name, number) { var delete_image_id = para_name + "_image" + number; var imagePathName = $("#" + delete_image_id).attr("src"); if (para_name == "waiguan") { $.get("deleteWaiguanImage.do", { deleteFile : imagePathName, t : Math.random() }, function(tag) { alert(tag); if (tag == "true") { $("#" + delete_image_id).attr("src", ""); $("#" + delete_image_id).css("visibility", "hidden"); $("#" + para_name + "_delete_image" + number).css("visibility", "hidden"); } else { alert("连接数据库失败,无法删除该图片!"); } }); } } /** * 重置上传按钮,使之为空 * * @param {} * para_name_add */ function resetUploadBotton(para_name_add) { var form = document.createElement("form"); var span = document.createElement("span"); var para_image_file = document.getElementById(para_name_add); para_image_file.parentNode.insertBefore(span, para_image_file); form.appendChild(para_image_file); form.reset(); span.parentNode.insertBefore(para_image_file, span); span.parentNode.removeChild(span); form.parentNode.removeChild(form); }
上传图片采用的是定义的form的submit()提交,iframe的异步提交。
返回操作将image的src的值,置为刚upload的图片在webroot中的位置,这样就能显示图片了。
删除图片时,利用Ajax将要删除的图片路径发送到后台,进行删除,删除成功时,将页面html中image的src值置为空。
后台处理的方法如下:
/** * 初始化SmartUpload类,用于上传文件 * * @param servlet * @return SmartUpload * @throws ServletException * @throws IOException * @throws SQLException */ public SmartUpload initSmartUpload(ActionServlet servlet) throws ServletException, IOException, SQLException { // 新建一个SmartUpload对象 SmartUpload su = new SmartUpload(); javax.servlet.jsp.PageContext pageContext = JspFactory .getDefaultFactory().getPageContext(servlet, request, response, null, true, 8192, true); // 上传初始化 su.initialize(pageContext); // 设定上传限制 // 1.限制每个上传文件的最大长度。 su.setMaxFileSize(10000000); // 2.限制总上传数据的长度。 su.setTotalMaxFileSize(20000000); // 3.设定允许上传的文件 su.setAllowedFilesList("jpg,gif,bmp,pcx," + "tiff,jpeg,tga,exif,fpx,cad"); // 4.设定禁止上传的文件 su.setDeniedFilesList("exe,bat,jsp,htm,html"); return su; } /** * 异步上传外观图 * * @param mapping * @param form * @param request * @param response * @return * @throws Exception */ public ActionForward uploadWaiguanImage(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { SeriesService seriesService = ServiceFactory.getSeriesService(request, response); String filePathName = null; boolean tag= true; try { //初始化SmartUpload对象 SmartUpload su = seriesService.initSmartUpload(this.getServlet()); //上传外观图,将文件存储在filePath中,遍历系列对象的外观图属性,将图片的位置存储在某一空的属性中 filePathName = "upload/" + seriesService.addWaiguanImage(su); } catch (Exception e) { e.printStackTrace(); tag = false; } PrintWriter out = response.getWriter(); if (tag == true) { out.println("<script>parent.callbackWaiguan(‘" + filePathName + "‘)</script>"); } else { out.println("<script>parent.callbackWaiguan(‘error‘)</script>"); } return null; } /** * 异步删除某个外观图 * * @param mapping * @param form * @param request * @param response * @return * @throws Exception */ public ActionForward deleteWaiguanImage(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception { Integer seriesID = (Integer) request.getSession().getAttribute( "seriesID"); String filePathName = (String) request.getParameter("deleteFile"); SeriesService seriesService = ServiceFactory.getSeriesService(request, response); boolean tag = true; try { //从数据库中和文件路径中删除外观图 tag = seriesService.deleteWaiguanImage(filePathName, seriesID); } catch (Exception e) { e.printStackTrace(); tag = false; } PrintWriter out = response.getWriter(); out.write(new Boolean(tag).toString()); return null; }
这样,便完成了要实现的功能。
时间: 2024-10-11 17:22:38