早上看到了Eclipse的帮助页面 有一个不错的进度条,所以很感兴趣.右键看了一下,原来就是用了个div的样式,然后异步请求进度处理信息.把处理的进度信息实时反应到页面上.
原理明白了.代码很简单.2个页面.一个负责显示,一个是异步处理页面.
1.progressBar.jsp
<%...@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%...
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!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>
<script language="JavaScript">...
function refresh()
...{
var nowNum=document.getElementById("nowNum").value;
progress_request_post(nowNum);
//window.location.replace("progressDo.jsp?nowNum="+nowNum);
if(nowNum<100)
setTimeout('refresh()', 500);
}
function progress_request_post(nowNum) ...{//初始化、指定处理函数、发送请求的函数
http_request = false;
var url='<%=basePath%>'+'progressDo.jsp?nowNum='+nowNum;
//alert("wwwwwwwwww"+encodeURI(url));
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest) ...{ //Mozilla 浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) ...{//设置MiME类别
http_request.overrideMimeType('text/xml');
}
}
else if (window.ActiveXObject) ...{ // IE浏览器
try ...{
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) ...{
try ...{
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) ...{}
}
}
if (!http_request) ...{ // 异常,创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
http_request.onreadystatechange = processRequest_ok;
//
// 确定发送请求的方式和URL以及是否同步执行下段代码
http_request.open("POST",encodeURI(url), true);
http_request.send(null);
}
// 处理返回信息的函数
// 处理返回信息的函数
function processRequest_ok()
...{
if (http_request.readyState == 4)
...{ // 判断对象状态
//alert("444444444!!");
/// popinfo(1);
if (http_request.status == 200)
...{ // 信息已经成功返回,开始处理信息
if((http_request.responseText)!=null&&(http_request.responseText).indexOf("false")>=0)...{
alert("返回失败");
//objimg.innerHTML=" ";
}
else if((http_request.responseText)!=null&&(http_request.responseText).indexOf("true")>=0)...{
//alert(http_request.responseText);
var index= http_request.responseText.indexOf("nowNum=");
var endIndex= http_request.responseText.indexOf("===");
if(index!=-1)...{
var nowNum=http_request.responseText.substring(index+7,endIndex);
//alert(nowNum);
document.getElementById("divProgress").style.width=nowNum+'px';
document.getElementById("progressValue").innerHTML=nowNum+'% 完成';
document.getElementById("nowNum").value=nowNum;
}
}
// alert("200!!");
}
else
...{ //页面不正常
// alert("服务器错误!!");
//objimg.innerHTML=" ";
}
}
}
</script>
</head>
<body dir="ltr">
<CENTER>
<input type=hidden name="nowNum" id="nowNum" value=1 >
<TABLE BORDER='0' id="progressTable">
<TR><TD>正在建立索引...</TD></TR>
<TR><TD ALIGN='LEFT'>
<DIV STYLE='width:100px;height:16px;border:1px solid ThreeDShadow;'>
<DIV ID='divProgress' STYLE='width:0px;height:100%;background-color:Highlight'></DIV>
</DIV>
</TD<
<%...
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!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>
<script language="JavaScript">...
function refresh()
...{
var nowNum=document.getElementById("nowNum").value;
progress_request_post(nowNum);
//window.location.replace("progressDo.jsp?nowNum="+nowNum);
if(nowNum<100)
setTimeout('refresh()', 500);
}
function progress_request_post(nowNum) ...{//初始化、指定处理函数、发送请求的函数
http_request = false;
var url='<%=basePath%>'+'progressDo.jsp?nowNum='+nowNum;
//alert("wwwwwwwwww"+encodeURI(url));
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest) ...{ //Mozilla 浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) ...{//设置MiME类别
http_request.overrideMimeType('text/xml');
}
}
else if (window.ActiveXObject) ...{ // IE浏览器
try ...{
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) ...{
try ...{
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) ...{}
}
}
if (!http_request) ...{ // 异常,创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
http_request.onreadystatechange = processRequest_ok;
//
// 确定发送请求的方式和URL以及是否同步执行下段代码
http_request.open("POST",encodeURI(url), true);
http_request.send(null);
}
// 处理返回信息的函数
// 处理返回信息的函数
function processRequest_ok()
...{
if (http_request.readyState == 4)
...{ // 判断对象状态
//alert("444444444!!");
/// popinfo(1);
if (http_request.status == 200)
...{ // 信息已经成功返回,开始处理信息
if((http_request.responseText)!=null&&(http_request.responseText).indexOf("false")>=0)...{
alert("返回失败");
//objimg.innerHTML=" ";
}
else if((http_request.responseText)!=null&&(http_request.responseText).indexOf("true")>=0)...{
//alert(http_request.responseText);
var index= http_request.responseText.indexOf("nowNum=");
var endIndex= http_request.responseText.indexOf("===");
if(index!=-1)...{
var nowNum=http_request.responseText.substring(index+7,endIndex);
//alert(nowNum);
document.getElementById("divProgress").style.width=nowNum+'px';
document.getElementById("progressValue").innerHTML=nowNum+'% 完成';
document.getElementById("nowNum").value=nowNum;
}
}
// alert("200!!");
}
else
...{ //页面不正常
// alert("服务器错误!!");
//objimg.innerHTML=" ";
}
}
}
</script>
</head>
<body dir="ltr">
<CENTER>
<input type=hidden name="nowNum" id="nowNum" value=1 >
<TABLE BORDER='0' id="progressTable">
<TR><TD>正在建立索引...</TD></TR>
<TR><TD ALIGN='LEFT'>
<DIV STYLE='width:100px;height:16px;border:1px solid ThreeDShadow;'>
<DIV ID='divProgress' STYLE='width:0px;height:100%;background-color:Highlight'></DIV>
</DIV>
</TD<