Servlet：htm+javascript+css+servlet （ajax）实现上传（能显示进度条）
本示例需要commons-fileupload-1.3.jar和commons-io-2.4.jar的支持，新手请参阅无进度条的上传
http://blog.csdn.net/tabactivity/article/details/11180631
确认您的环境配置成功后，下面开始编码：
src/UploadStatus.java ，数据模型类
package com.xieyuan;
public class UploadStatus {
private long bytesRead;
private long contentLength;
private int items;
private long startTime = System.currentTimeMillis();
public long getBytesRead() {
return bytesRead;
}
public void setBytesRead(long bytesRead) {
this.bytesRead = bytesRead;
}
public long getContentLength() {
return contentLength;
}
public void setContentLength(long contentLength) {
this.contentLength = contentLength;
}
public int getItems() {
return items;
}
public void setItems(int items) {
this.items = items;
}
public long getStartTime() {
return startTime;
}
public void setStartTime(long startTime) {
this.startTime = startTime;
}
}
src/UploadListener.java，继承自ProgressListener，当使用commons_uploadfile组件上传时，调用组件类的方法可添加上传监听，组件就会不断调用UploadListener的update方法
package com.xieyuan;
import org.apache.commons.fileupload.ProgressListener;
public class UploadListener implements ProgressListener {
private UploadStatus status;
public UploadListener(UploadStatus status) {
this.status = status;
}
public void update(long bytesRead, long contentLength, int items) {
status.setBytesRead(bytesRead);
status.setContentLength(contentLength);
status.setItems(items);
}
}
src/UploadServlet.java，该类doPost方法用于处理上传，index.jsp后台会使用XmlHttpRequest调用本Servlet的doGet方法，从session中获取最新的上传数据情况
package com.xieyuan;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sound.sampled.AudioFormat.Encoding;
import org.apache.commons.fileupload.DiskFileUpload;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class UploadServlet extends HttpServlet {
//定义临时文件盒上传文件的存储路径
private File uploadTemp=null;
private File uploadPath=null;
/**
* Constructor of the object.
*/
public UploadServlet() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//禁用缓存,index.jsp后台会使用XmlHttpRequest调用本Servlet的doGet方法，从session中获取最新的上传数据情况
response.setHeader("Cache-Control", "no-store");
response.setHeader("Pragrma", "no-cache");
response.setDateHeader("Expires", 0);
response.setContentType("text/html;charset=utf-8");
UploadStatus status = (UploadStatus) request.getSession(true)
.getAttribute("uploadStatus");
if (status == null) {
response.getWriter().println("没有上传信息");
return;
}
long startTime = status.getStartTime();
long currentTime = System.currentTimeMillis();
// 已传输的时间 单位：s
long time = (currentTime - startTime) / 1000 + 1;
// 传输速度 单位：byte/s
double velocity = ((double) status.getBytesRead()) / (double) time;
// 估计总时间 单位：s
double totalTime = status.getContentLength() / velocity;
// 估计剩余时间 单位：s
double timeLeft = totalTime - time;
// 已完成的百分比
int percent = (int) (100 * (double) status.getBytesRead() / (double) status
.getContentLength());
// 已完成数 单位：M
double length = ((double) status.getBytesRead()) / 1024 / 1024;
// 总长度 单位：M
double totalLength = ((double) status.getContentLength()) / 1024 / 1024;
// 格式：百分比||已完成数(M)||文件总长度(M)||传输速率(K)||已用时间(s)||估计总时间(s)||估计剩余时间(s)||正在上传第几个文件
String value = percent + "||" + length + "||" + totalLength + "||"
+ velocity + "||" + time + "||" + totalTime + "||" + timeLeft
+ "||" + status.getItems();
response.getWriter().println(value);
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
File file=null;
String description=null;
//设置响应格式（不设置请求格式，因为文件是二进制的，不能使用UTF-8格式化请求数据）
response.setContentType("text/html;charset=utf-8");
PrintWriter out=response.getWriter();
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println("<HEAD><TITLE>文件上传</TITLE></HEAD>");
out.println("<BODY style='margin:50px'>");
out.println("上传日志：<BR/>");
UploadStatus status=new UploadStatus();
UploadListener listener=new UploadListener(status);
/*
*
* 把 UploadStatus 放到 session 里,引用
返回与此请求关联的当前HttpSession，如果没有当前会话和创造是真实的，返回一个新的会话。
如果创建是假的，并要求有没有有效的HttpSession，这个方法返回null。
*/
request.getSession(true).setAttribute("uploadStatus", status);
//创建基于磁盘的工厂，针对大文件，临时文件将存储在磁盘
DiskFileItemFactory factory=new DiskFileItemFactory();
//设置缓冲区大小,超出该文件直接写入到磁盘的大小设置门槛。
factory.setSizeThreshold(10240); //这里默认10KB
//设置用于大于配置的大小阈值设置的临时存储文件目录。
factory.setRepository(uploadTemp);
//创建一个文件上传的句柄
ServletFileUpload upload=new ServletFileUpload(factory);
//设置最大文件尺寸 ，这里是40MB
upload.setSizeMax(41943040);
upload.setHeaderEncoding("utf-8");
// 设置 listener
upload.setProgressListener(listener);
try {
//将解析结果放在LIST中
List<FileItem> list =upload.parseRequest(request);
out.println("遍历所有的 FileItem ... <br/>");
// 遍历 list 中所有的 FileItem
for(FileItem item:list)
{
// 如果是 文本域
if(item.isFormField())
{
if(item.getFieldName().equals("description1")||item.getFieldName().equals("description2"))
{
description = item.getString("UTF-8");
System.out.println("遍历到 "+item.getFieldName()+" ... <br/>"+description+"<BR/>");
}
}
else
{
//否则为文件域,当getName为Null说明没有选则文件
if((item.getFieldName().equals("file1")||item.getFieldName().equals("file2"))
&&item.getName()!=null&&!item.getName().equals(""))
{
try
{
// 统一 Linux 与 windows 的路径分隔符
String fileName = item.getName();
//fileName = fileName.substring(fileName.lastIndexOf("\\"));
// 服务器端文件，放在 upload 文件夹下
file=new File(uploadPath,fileName);
if(!file.getParentFile().exists())
file.getParentFile().mkdirs();
if(!file.exists())
file.createNewFile();
item.write(file);
System.out.println("遍历到 "+fileName+" ... <br/>"+description+"<BR/>");
} catch (Exception e) {
System.out.println("Request 上传失败！"+e.getMessage());
}
finally //总是立即删除保存表单字段内容的临时文件
{
item.delete();
}
}
}
}
System.out.println("Request 解析完毕,文件上传完毕！");
} catch (Exception e) {
System.out.println("Request 解析异常！"+e.getMessage());
}
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
uploadPath=new File(this.getServletContext().getRealPath("upload"));
if(!uploadPath.exists())
uploadPath.mkdirs();
uploadTemp=new File(this.getServletContext().getRealPath("upload/temp"));
if(!uploadTemp.exists())
uploadTemp.mkdirs();
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>UploadServlet</servlet-name>
<servlet-class>com.xieyuan.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/servlet/UploadServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
WebRoot / index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>带进度条的文件上传</title>
<style type="text/css">
#progressBar{width:400px;height:12px;background:#FFFFFF;border:1px solid #000000;padding:1px;}
#progressBarItem{width:30%;height:100%;background:#FF0000;}
</style>
<script type="text/JavaScript">
<!--默认为已经完成上传操作-->
var _finished=true;
function $(obj)
{
return document.getElementById(obj);
}
<!--显示进度条等信息-->
function showStatus()
{
_finished=false;
$('status').style.display='block';
$('progressBarItem').style.width='1%';
$('btnSubmit').disabled=true;
<!--隔1秒后执行一次-->
setTimeout("requestStatus()",1000);
}
<!--发送请求获取文件上传状态-->
function requestStatus()
{
if(_finished)
return;
var req=createRequest();
req.open("GET","servlet/UploadServlet");
req.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
req.onreadystatechange=function(){callback(req);};
//我们的实例在 open() 的第三个参数中使用了 "true"。该参数规定请求是否异步处理。
//True 表示脚本会在 send() 方法之后继续执行，而不等待来自服务器的响应。
req.send(null);
setTimeout("requestStatus()",1000);
}
function createRequest()
{
if(window.XMLHttpRequest)//ns
{
return new XMLHttpRequest();
}else//IE
{
try{
return new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
return null;
}
function callback(req)
{
//请求结束后
if(req.readyState==4)
{
//如果发生错误，则显示错误信息
if(req.status!=200)
{
_debug("发生错误。 req.status: " + req.status + "");
return;
}
var ss = req.responseText.split("||");
// 格式：百分比||已完成数(M)||文件总长度(M)||传输速率(K)||已用时间(s)||估计总时间(s)||估计剩余时间(s)||正在上传第几个文件
$('progressBarItem').style.width = '' + ss[0] + '%';
$('statusInfo').innerHTML = '已完成百分比: ' + ss[0] + '% <br />已完成数(M): ' + ss[1] + '<br/>文件总长度(M): ' + ss[2] + '<br/>传输速率(K): ' + ss[3] + '<br/>已用时间(s): ' + ss[4] + '<br/>估计总时间(s): ' + ss[5] + '<br/>估计剩余时间(s): ' + ss[6] + '<br/>正在上传第几个文件: ' + ss[7];
if(ss[1] == ss[2])
{
_finished = true;
$('statusInfo').innerHTML += "<br/><br/><br/>上传已完成。";
$('btnSubmit').disabled = false;
}
_debug("status.jsp 返回值：" + req.responseText);
}
}
function _debug(obj)
{
//var div=document.createElement("DIV");
$('debug').innerHTML="[debug]:"+obj+"<br/>";
//document.body.appendChild(div);
}
</script>
</head>
<body style="margin:50px">
<iframe name="upload_iframe" width="0" height="0" frameborder="0" ></iframe>
<form action="servlet/UploadServlet" method="post" enctype="multipart/form-data"
target="upload_iframe" onsubmit="showStatus();">
<p>上传文件：</p>
文件1：<input type="file" name="file1" /><br/>
描述：<input type="text" name="description1" /><br/>
文件2：<input type="file" name="file2" /><br/>
描述：<input type="text" name="description2" /><br/>
<input type="submit" id="btnSubmit" value=" 上 传 " />
</form>
<div id="status" style="display:none;position:relative;line-height:100%;opacity:1;">
上传进度：
<div id="progressBar" ><div id="progressBarItem" /></div>
<div id="statusInfo" style="margin:10px 0px 0px 0px;"/>
</div>
<BR/>
<div id="debug" />
</body>
</html>
通过访问：http://127.0.0.1:8080/Test/ 查看程序效果，如图
System.out.println打印的运行情况
至此，一个简单的上传程序就完成了。
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