文件上传---动作条
时间:2022-04-22
本文章向大家介绍文件上传---动作条，主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项，具有一定的参考价值，需要的朋友可以参考一下。
利用Apache commons fileupload上传文件，直接显示其完成的进度条。----示例代码源自《JAVA WEB王者归来》
1 首先要显示动作条要利用Ajax的异步请求，使得在没有完成时，不会刷新本页，而是局部的刷新。如果没有指定form的定向页面，默认是刷新本页，正常我们提交一个form刷新本页，在没有完成请求前是显示空白的网页，这里我们指定他刷新一个不显示的区域，就要用到form的属性target。
<iframe name=uploadiframe width=0 height=0></iframe>
<form action="servlet/ProgressUploadServlet" method="post" enctype="multipart/form-data"
target="uploadiframe" onsubmit="showStatus();">
<input type="file" name="file1" style="width:350px;"/><br/>
<input type="file" name="file2" style="width:350px;"/><br/>
<input type="file" name="file3" style="width:350px;"/><br/>
<input type="submit" value="submit" id="btnSubmit"/>
</form> 2 我们创建一个status的bean，用来保存一些状态信息，比如名字，读取的长度，读取的字节大小，时间等等。
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;
}
}3 创建一个监听器实时的获取状态信息
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);
}
}4 form表单用pos方法提交后，在doPost里面获取状态信息，保存到session中。在本页面，在自动用get方法读取session中的信息，返回给网页，网页动态的进行数据的显示。
doPost
UploadStatus status = new UploadStatus();
UploadListener listener = new UploadListener(status);
request.getSession(true).setAttribute("uploadStatus",status);
ServletFileUpload upload = new ServletFileUpload(new DiskFileItemFactory());
upload.setProgressListener(listener);doGet
long startTime = status.getStartTime();
long currentTime = System.currentTimeMillis();
long time = (currentTime - startTime)/1000 + 1;
double velocity = ((double)status.getBytesRead())/(double)time;
double totalTime = status.getContentLength()/velocity;
double timeLeft = totalTime - time;
int percent = (int)(100*(double)status.getBytesRead()/(double)status.getContentLength());
double length = ((double)status.getBytesRead())/1024/1024;
double totalLength = ((double)status.getContentLength())/1024/1024;
String value = percent +"||" + length + "||" +totalLength+"||"+
velocity+"||"+time+"||"+totalTime+"||"+timeLeft+"||"+status.getItems();
response.getWriter().println(value);js
<script type="text/javascript">
var finished = true;
function $(obj){
return document.getElementById(obj);
}
function showStatus(){
finished = false;
$('status').style.display = 'block';
$('progressBarItem').style.width = '1%';
$('btnSubmit').disabled = true;
setTimeout("requestStatus()",1000);
}
function requestStatus(){
if(finished) return;
var req = createRequest();
req.open("GET","servlet/ProgressUploadServlet");
req.onreadystatechange = function(){callback(req);}
req.send(null);
setTimeout("requestStatus()",1000);
}
function createRequest(){
if(window.XMLHttpRequest){
return new XMLHttpRequest();
}else{
try{
return new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
return null;
}
function callback(req){
if(req.readyState == 4){
if(req.status != 200){
debug("error! req.status:"+req.status+"");
return ;
}
debug("status.jsp return value:"+req.responseText);
var ss = req.responseText.split("||");
$('progressBarItem').style.width = ''+ss[0]+'%';
$('statusInfo').innerHTML = 'end of total:'+ss[0] +'%<br/>'+
'sucess of numbers:'+ss[1]+'<br/>'+
'length of file:'+ss[2]+'<br/>'+
'velocity of trans:'+ss[3]+'<br/>'+
'the time used:'+ss[4]+'<br/>'+
'total time:'+ss[5]+'<br/>'+
'other time:'+ss[6]+'<br/>'+
'which is translating:'+ss[7];
if(ss[1] == ss[2]){
finished = true;
$('statusInfo').innerHTML += "<br/><br/><br/>have done!";
$('btnSubmit').disabled = false;
}
}
}
function debug(obj){
var div = document.createElement("DIV");
div.innerHTML = "[debug]:"+obj;
document.body.appendChild(div);
}
</script>全部代码：
progressFileupload.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'progressFileupload.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<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>
</head>
<body>
<iframe name=uploadiframe width=0 height=0></iframe>
<form action="servlet/ProgressUploadServlet" method="post" enctype="multipart/form-data"
target="uploadiframe" onsubmit="showStatus();">
<input type="file" name="file1" style="width:350px;"/><br/>
<input type="file" name="file2" style="width:350px;"/><br/>
<input type="file" name="file3" style="width:350px;"/><br/>
<input type="submit" value="submit" id="btnSubmit"/>
</form>
<div id="status" style="display:none;">
uploadbar:
<div id="progressBar"><div id="progressBarItem"></div></div>
<div id="statusInfo"></div>
</div>
<script type="text/javascript">
var finished = true;
function $(obj){
return document.getElementById(obj);
}
function showStatus(){
finished = false;
$('status').style.display = 'block';
$('progressBarItem').style.width = '1%';
$('btnSubmit').disabled = true;
setTimeout("requestStatus()",1000);
}
function requestStatus(){
if(finished) return;
var req = createRequest();
req.open("GET","servlet/ProgressUploadServlet");
req.onreadystatechange = function(){callback(req);}
req.send(null);
setTimeout("requestStatus()",1000);
}
function createRequest(){
if(window.XMLHttpRequest){
return new XMLHttpRequest();
}else{
try{
return new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
return new ActiveXObject("Microsoft.XMLHTTP");
}
}
return null;
}
function callback(req){
if(req.readyState == 4){
if(req.status != 200){
debug("error! req.status:"+req.status+"");
return ;
}
debug("status.jsp return value:"+req.responseText);
var ss = req.responseText.split("||");
$('progressBarItem').style.width = ''+ss[0]+'%';
$('statusInfo').innerHTML = 'end of total:'+ss[0] +'%<br/>'+
'sucess of numbers:'+ss[1]+'<br/>'+
'length of file:'+ss[2]+'<br/>'+
'velocity of trans:'+ss[3]+'<br/>'+
'the time used:'+ss[4]+'<br/>'+
'total time:'+ss[5]+'<br/>'+
'other time:'+ss[6]+'<br/>'+
'which is translating:'+ss[7];
if(ss[1] == ss[2]){
finished = true;
$('statusInfo').innerHTML += "<br/><br/><br/>have done!";
$('btnSubmit').disabled = false;
}
}
}
function debug(obj){
var div = document.createElement("DIV");
div.innerHTML = "[debug]:"+obj;
document.body.appendChild(div);
}
</script>
</body>
</html>UploadStatus.java
package com.test.temp;
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;
}
}UploadListener.java
package com.test.temp;
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);
}
}PorgressUploadServlet.java
package com.test.hello;
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.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.test.temp.UploadListener;
import com.test.temp.UploadStatus;
public class ProgressUploadServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public ProgressUploadServlet() {
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 {
response.setHeader("Cache-Control","no-store");
response.setHeader("Pragrma","no-cache");
response.setDateHeader("Expires",0);
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();
long time = (currentTime - startTime)/1000 + 1;
double velocity = ((double)status.getBytesRead())/(double)time;
double totalTime = status.getContentLength()/velocity;
double timeLeft = totalTime - time;
int percent = (int)(100*(double)status.getBytesRead()/(double)status.getContentLength());
double length = ((double)status.getBytesRead())/1024/1024;
double totalLength = ((double)status.getContentLength())/1024/1024;
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 {
UploadStatus status = new UploadStatus();
UploadListener listener = new UploadListener(status);
request.getSession(true).setAttribute("uploadStatus",status);
ServletFileUpload upload = new ServletFileUpload(new DiskFileItemFactory());
upload.setProgressListener(listener);
try{
List itemList = upload.parseRequest(request);
for(Iterator it = itemList.iterator();it.hasNext();){
FileItem item = (FileItem)it.next();
if(item.isFormField()){
System.out.println("FormField:"+item.getFieldName()+"="+item.getString());
}else{
System.out.println("File:"+item.getName());
String fileName = item.getName().replace("/","\");
fileName = fileName.substring(fileName.lastIndexOf("\"));
File saved = new File("D:\upload_temp",fileName);
saved.getParentFile().mkdirs();
InputStream ins = item.getInputStream();
OutputStream ous = new FileOutputStream(saved);
byte[] tmp = new byte[1024];
int len = -1;
while((len = ins.read(tmp)) != -1){
ous.write(tmp,0,len);
}
ous.close();
ins.close();
response.getWriter().println("已保存文件："+saved);
}
}
}catch(Exception e){
response.getWriter().println("上传发生错误:"+e.getMessage());
}
// response.setContentType("text/html");
// PrintWriter out = response.getWriter();
// out
// .println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">");
// out.println("<HTML>");
// out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
// out.println(" <BODY>");
// out.print(" This is ");
// out.print(this.getClass());
// out.println(", using the POST method");
// out.println(" </BODY>");
// out.println("</HTML>");
// out.flush();
// out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}
}web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.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>PostServlet</servlet-name>
<servlet-class>com.test.hello.PostServlet</servlet-class>
</servlet>
<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>test</servlet-name>
<servlet-class>com.test.hello.test</servlet-class>
</servlet>
<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.test.hello.UploadServlet</servlet-class>
</servlet>
<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>ProgressUploadServlet</servlet-name>
<servlet-class>com.test.hello.ProgressUploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>PostServlet</servlet-name>
<url-pattern>/servlet/PostServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>/servlet/test</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/servlet/UploadServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>ProgressUploadServlet</servlet-name>
<url-pattern>/servlet/ProgressUploadServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>运行结果：
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