項目源代碼下載：http://download.csdn.net/detail/nuptboyzhb/6262253
1.簡介
本文主要演示Jquery progressbar的進度條功能。js通過ajax請求向后台實時獲取當前的進度值。后台將進度值存儲在cookie中，每次請求后，將進度條的值增2個。以此演示進度條的實時顯示功能。
2.前台index.jsp
jsp代碼如下
<%@ 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"> -->
<!DOCTYPE html>
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<link rel="stylesheet" type="text/css" href="js/themes/default/easyui.css">
<link rel="stylesheet" type="text/css" href="js/themes/icon.css">
<link rel="stylesheet" type="text/css" href="js/demo/demo.css">
<script type="text/javascript" src="js/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.easyui.min.js"></script>
<script type='text/javascript'>
var timerId;
$(function(){
//每隔0.5秒自動調用方法，實現進度條的實時更新
timerId=window.setInterval(getForm,500);
});
function getForm(){
//使用JQuery從后台獲取JSON格式的數據
$.ajax({
type:"post",//請求方式
url:"getProgressValueByJson",//發送請求地址
timeout:30000,//超時時間：30秒
dataType:"json",//設置返回數據的格式
//請求成功后的回調函數 data為json格式
success:function(data){
if(data.progressValue>=100){
window.clearInterval(timerId);
}
$('#p').progressbar('setValue',data.progressValue);
},
//請求出錯的處理
error:function(){
window.clearInterval(timerId);
alert("請求出錯");
}
});
}
</script>
</head>
<body>
<div style="margin:100px 0;"></div>
<div id="p" class="easyui-progressbar" style="width: 400px;"></div>
</body>
</html>
3.struts.xml文件的配置
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.devMode" value="true" />
<package name="front" extends="struts-default" namespace="/">
<action name="getProgressValueByJson" class="edu.njupt.zhb.test.TestAction" method="getProgressValueByJson">
<result name="success"></result>
</action>
<action name="TestAction" class="edu.njupt.zhb.test.TestAction">
<result type="httpheader"></result>
</action>
</package>
</struts>
4.后台的java代碼（）
package edu.njupt.zhb.test;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
/*
*@author: ZhengHaibo
*web: http://blog.csdn.net/nuptboyzhb
*mail: zhb931706659@126.com
*Sep 13, 2013 Nanjing,njupt,China
*/
public class TestAction extends ActionSupport {
/**
*
*/
private static final long serialVersionUID = -8697049781798812644L;
/**
* 通過Ajax獲取json格式的ProgressBar值
* Type：Action
*/
public void getProgressValueByJson(){
String progressValueString = getCookie(getRequest(),"progressValue");
int progressValue = Integer.parseInt(progressValueString);
if(progressValue>100){
progressValue = 0;
}
System.out.println(" getCookie:---progressValue="+progressValue);
writeJsonString("{\"progressValue\":\"" + progressValue + "\"}");
progressValue += 2;
setCookie(getResponse(),"progressValue",progressValue+"",365*24*60*60);
}
/**
* Get HttpServletRequest Object
* @return HttpServletRequest
*/
public HttpServletRequest getRequest(){
return ServletActionContext.getRequest();
}
/**
* Get HttpServletResponse Object
* @return HttpServletResponse
*/
protected HttpServletResponse getResponse() {
return ServletActionContext.getResponse();
}
/**
* Get PrintWriter Object
* @return PrintWriter
* @throws IOException
*/
protected PrintWriter getWriter() throws IOException {
return this.getResponse().getWriter();
}
/**
* 寫Json格式字符串
* @param json
*/
protected void writeJsonString(String json) {
try {
getResponse().setContentType("text/html;charset=UTF-8");
this.getWriter().write(json);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 獲取cookie
* @param request
* @param name
* @return String
*/
public static String getCookie(HttpServletRequest request, String name) {
String value = null;
try {
for (Cookie c : request.getCookies()) {
if (c.getName().equals(name)) {
value = c.getValue();
}
}
} catch (Exception e) {
e.printStackTrace();
}
return value;
}
/**
* 設置cookie
* @param response
* @param name
* @param value
* @param period
*/
public static void setCookie(HttpServletResponse response, String name, String value, int period) {
try {
Cookie div = new Cookie(name, value);
div.setMaxAge(period);
response.addCookie(div);
} catch (Exception e) {
e.printStackTrace();
}
}
}
5.運行
將項目部署到Tomcat上之后，在瀏覽器中輸入URL，則可以看到進度條逐漸更新
