利用DWR开发基于Ajax的文件上载portlet

＜!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"
"http://getahead.org/dwr//dwr20.dtd"＞

＜dwr＞
＜allow＞
＜create creator="new" javascript="FileUploadProgressListener"＞
＜param name="class"
value="uk.ac.dl.esc.gtg.myportlets.fileupload.FileUploadProgressListener"/＞
＜include method="getFileUploadStatus"/＞
＜/create＞
＜/allow＞
＜/dwr＞

＜%@ page session="false" %＞
＜%@ page contentType="text/html" %＞
＜%@ page import="javax.portlet.PortletURL" %＞
＜%@ taglib uri="http://java.sun.com/portlet" prefix="portlet" %＞
＜portlet:defineObjects/＞

＜script type="text/javascript"
src='＜%= renderResponse.encodeURL(renderRequest.getContextPath()
+ "/dwr/interface/FileUploadProgressListener.js") %＞'＞ 
＜/script＞

＜script type="text/javascript"
src='＜%= renderResponse.encodeURL(renderRequest.getContextPath()
+ "/dwr/engine.js") %＞'＞ 
＜/script＞

＜script type="text/javascript"
src='＜%= renderResponse.encodeURL(renderRequest.getContextPath()
+ "/dwr/util.js") %＞'＞ 
＜/script＞

＜script type="text/javascript"＞
function fileupload_ajax_query_upload_status() {
FileUploadProgressListener.getFileUploadStatus

(fileupload_ajax_show_upload_status); 
return true; 
}

function fileupload_ajax_show_upload_status(status) {
if (status == "100")
document.getElementById("fileupload_progress").innerHTML
="File successfully uploaded"; 
else {
document.getElementById("progressBar").style.display = "block"; 
document.getElementById("fileupload_progress").innerHTML=
"Uploading file: " + status
+ "% completed, please wait..."; 
document.getElementById("progressBarBoxContent").style.width =
parseInt(status * 3.5) + "px"; 
setTimeout(fileupload_ajax_query_upload_status, 2000); 
}

return true; 
}
＜/script＞

＜style type="text/css"＞
#progressBar {padding-top: 5px; }
#progressBarBox {width: 350px; height: 20px; border: 1px insert; background: #eee; }
#progressBarBoxContent {width: 0; height: 20px; border-right: 1px solid #444; 
background: #9ACB34; }
＜/style＞

＜h4＞File Upload＜/h4＞

＜!-- the upload form --＞
＜% PortletURL pUrl = renderResponse.createActionURL(); 
%＞
＜form action="＜%= pUrl.toString() %＞"
enctype="multipart/form-data" method="post"
onsubmit="setTimeout('fileupload_ajax_query_upload_status()', 1000)"＞

＜input type="file" name="fileupload_upload" value="Upload File"＞
＜input type="submit" value="Upload"＞
＜/form＞

＜%-- file upload progress bar --%＞
＜div id="fileupload_progress"＞＜/div＞
＜div id="progressBar" style="display: none; "＞
＜div id="progressBarBoxContent"＞＜/div＞
＜/div＞

commons-fileupload-1.2/commons-fileupload-1.2.jar 
commons-io-1.3/commons-io-1.3.jar 
commons-logging-1.0.4/commons-logging-1.0.4.jar 
dwr-2.0.1/dwr.jar 
portletapi-1.0/portlet.jar 
servletapi-2.4/servletapi-2.4.jar