使用jQuery+SWFUpload+Commons-FileUpload实现带进度条的上传
这两天在找一个可以实现上传时显示进度的ajax库，看了很多10 best ajax uploader之类的文章，发现里面很多链接都点不进去，或者网站文档和demo做得很烂，我这人选开源软件用，一定会看他的文档做得怎么样，做得不全就懒得研究了，swfupload文档做得也不好，例子太少，没有讲解，不过本着矬子里面拔高个的原则只能将就着用它了。外国有个人实现了一个swfuload的jquery插件，主要是完善swfupload的事件机制的，可以点这里去看看,结合这个插件，做多文件上传加进度条是件很easy的事情。官网的例子偏偏没有后端是java的例子，我又google了一番，试用了一下commons-fileupload，感觉很方便，于是就整出了一个例子来，前端是参照这个做了些修改。btw,iteye有好几篇是讲swfupload+java实现上传的，后端是个jsp自己实现的保存上传文件的，我下载了一下代码，发现一模一样，也不知是谁抄谁的，都宣称原创，好笑。
1.前面选择上传文件的页面upload.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<link href="css/default.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="js/swfupload.js"></script>
<script type="text/javascript" src="js/swfupload.queue.js"></script>
<script type="text/javascript" src="js/fileprogress.js"></script>
<script type="text/javascript" src="js/handlers.js"></script>
<script type="text/javascript" src="js/jquery-1.4.3.js"></script>
<script type="text/javascript" src="js/jquery.swfupload.js"></script>
<style type="text/css">
#swfupload-control p {
margin: 10px 5px;
font-size: 0.9em;
}
#log {
margin: 0;
padding: 0;
width: 500px;
}
#log li {
list-style-position: inside;
margin: 2px;
border: 1px solid #ccc;
padding: 10px;
font-size: 15px;
font-family: Arial, Helvetica, sans-serif;
color: #333;
background: #fff;
position: relative;
}
#log li .progressbar {
border: 1px solid #333;
height: 18px;
background: #fff;
}
#log li .progress {
background: rgba(104, 133, 127, 0.52);
width: 0%;
height: 18px;
}
#log li p {
margin: 0;
line-height: 18px;
}
#log li.success {
border: 1px solid #339933;
background: #ccf9b9;
}
#log li span.stopUpload {
position: absolute;
top: 5px;
right: 5px;
width: 20px;
height: 20px;
background: url('js/swfupload/cancel.png') no-repeat;
cursor: pointer;
}
#img span.cancel {
background: url('js/swfupload/cancel.png') no-repeat;
}
</style>
<script type="text/javascript">
$(function () {
$('#swfupload-control').swfupload({
upload_url:"handler/doUpload",
file_post_name:'uploadfile',
file_size_limit:"20000 MB",
file_types:"*.*",
file_types_description:"All files",
flash_url:"js/swfupload.swf",
button_image_url:'js/swfupload/wdp_buttons_upload_114x29.png',
button_width:114,
button_height:29,
button_placeholder:$('#button')[0],
})
.bind('fileQueued', function (event, file) {
var listitem = '<li id="' + file.id + '" >' +
'File: <em>' + file.name + '</em> (' + Math.round(file.size / 1024) + ' KB) <span class="progressvalue" ></span>' +
'<div class="progressbar" ><div class="progress" ></div></div>' +
'<p class="status" >Pending</p>' +
'<span class="stopUpload" > </span>' +
'</li>';
$('#log').append(listitem);
$('li#' + file.id + ' .stopUpload').bind('click', function () { //Remove from queue on cancel click
var swfu = $.swfupload.getInstance('#swfupload-control');
swfu.cancelUpload(file.id);
$('#log li#' + file.id).find('p.status').text('Canceled');
$('#log li#' + file.id).find('span.stopUpload').css('background-image','none')
$('#log li#' + file.id).find('span.stopUpload').css('cursor','defult')
// $('li#' + file.id).slideUp('fast');
});
// start the upload since it's queued
$(this).swfupload('startUpload');
})
.bind('fileQueueError', function (event, file, errorCode, message) {
//alert('Size of the file '+file.name+' is greater than limit');
alert(errorCode+":"+message)
})
.bind('fileDialogComplete', function (event, numFilesSelected, numFilesQueued) {
$('#queuestatus').text('Files Selected: ' + numFilesSelected + ' / Queued Files: ' + numFilesQueued);
})
.bind('uploadStart', function (event, file) {
$('#log li#' + file.id).find('p.status').text('Uploading...');
$('#log li#' + file.id).find('span.progressvalue').text('0%');
$('#log li#' + file.id).find('span.cancel').hide();
})
.bind('uploadProgress', function (event, file, bytesLoaded) {
//Show Progress
var percentage = Math.round((bytesLoaded / file.size) * 100);
$('#log li#' + file.id).find('div.progress').css('width', percentage + '%');
$('#log li#' + file.id).find('span.progressvalue').text(percentage + '%');
})
.bind('uploadSuccess', function (event, file, serverData) {
var item = $('#log li#' + file.id);
item.find('div.progress').css('width', '100%');
item.find('span.progressvalue').text('100%');
item.addClass('success').find('p.status').html('Done!!! ');
$('#log li#' + file.id).find('span.stopUpload').css('background-image','none') ;
$('#log li#' + file.id).find('span.stopUpload').css('cursor','default') ;
})
.bind('uploadComplete', function (event, file) {
// upload has completed, try the next one in the queue
$(this).swfupload('startUpload');
})
});
</script>
</head>
<body>
<div id="swfupload-control">
<p>Select files of any type, muliple files are allowed to select every time.</p>
<input type="button" id="button"/>
<p id="queuestatus"></p>
<ol id="log"></ol>
</div>
</body>
</html>
取消按钮的那个class如果叫cancel(原始例子是叫这个名字的)，是不好用的，html里总是有一些诡异的保留字在等着我们，我改成stopUpload就好用了。
2.后端保存文件的servlet
package com.offspring.servlet;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
public class Upload extends javax.servlet.http.HttpServlet {
public static final int MB = 1024 * 1024;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws javax.servlet.ServletException, IOException {
DiskFileItemFactory fileItemFactory = new DiskFileItemFactory(10 * MB, new File("d:/temp4"));
ServletFileUpload uploader = new ServletFileUpload(fileItemFactory);
uploader.setSizeMax(1200 * MB);
List fields = null;
try {
fields = uploader.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
return;
}
Iterator iter = fields.iterator();
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();
if (!item.isFormField()) {
try {
processUploadedFile(item);
} catch (Exception e) {
e.printStackTrace();
return;
}
}
}
response.getOutputStream().println("200 OK");
}
private void processUploadedFile(FileItem item) throws Exception {
String basePath = "d:\\temp\\upload\\";
item.write(new File(basePath + item.getName()));
System.out.println("write file to '"+basePath + item.getName()+"'");
}
}
运行时截图：
你同时选多个文件也是可以的，不过仍然一次上传一个，一个传完了，下一个会自动开启上传。
3.实现进度条的原理
swfupload提供了很多事件，结合jquery可以绑定相应的回调函数， 比如uploadProgress会在上传过程中定期被触发，你在这个回调里写个用css更新进度条宽度就OK了。
.bind('uploadProgress', function (event, file, bytesLoaded) {
//Show Progress
var percentage = Math.round((bytesLoaded / file.size) * 100);
$('#log li#' + file.id).find('div.progress').css('width', percentage + '%');
$('#log li#' + file.id).find('span.progressvalue').text(percentage + '%');
})
不过记得在linux上 uploadProgress 只会在上传结束时才触发，这是linux上flash的一个bug。本来写得很多，在firefox上上传附件不好用，然后文字还变成了乱码，这是怎么搞的？
代码可以在附件中找到 。