本文主要演示Jquery progressbar的进度条功能。js通过ajax请求向后台实时获取当前的进度值。后台将进度值存储在cookie中，每次请求后，将进度条的值增2个。以此演示进度条的实时显示功能。
前台index.jsp
jsp代码如下
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"https://www.jb51.net/"; %> <!-- <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> --> <!DOCTYPE html> <html> <head> <base href="https://www.jb51.net/<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <link type="text/css" href="https://www.jb51.net/js/themes/default/easyui.css"> <link type="text/css" href="https://www.jb51.net/js/themes/icon.css"> <link type="text/css" href="https://www.jb51.net/js/demo/demo.css"> <script type="text/javascript" src="https://www.jb51.net/js/jquery.min.js"></script> <script type="text/javascript" src="https://www.jb51.net/js/jquery.easyui.min.js"></script> <script type='text/javascript'> var timerId; $(function(){ //每隔0.5秒自动调用方法，实现进度条的实时更新 timerId=window.setInterval(getForm,500); }); function getForm(){ //使用JQuery从后台获取JSON格式的数据 $.ajax({ type:"post",//请求方式 url:"getProgressValueByJson",//发送请求地址 timeout:30000,//超时时间：30秒 dataType:"json",//设置返回数据的格式 //请求成功后的回调函数 data为json格式 success:function(data){ if(data.progressValue>=100){ window.clearInterval(timerId); } $('#p').progressbar('setValue',data.progressValue); }, //请求出错的处理 error:function(){ window.clearInterval(timerId); alert("请求出错"); } }); } </script> </head> <body> <div></div> <div></div> </body> </html>
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 value="true" /> <package extends="struts-default" namespace="https://www.jb51.net/"> <action method="getProgressValueByJson"> <result></result> </action> <action> <result type="httpheader"></result> </action> </package> </struts>
后台的java代码（）
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: *mail: zhb931706659@126.com *Sep 13, 2013 Nanjing,njupt,China */ public class TestAction extends ActionSupport { /** * */ private static final long serialVersionUID = -8697049781798812644L; /** * 通过Ajax获取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(); } /** * 写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(); } } /** * 获取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; } /** * 设置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(); } } }
运行
将项目部署到Tomcat上之后，在浏览器中输入URL，则可以看到进度条逐渐更新
源码下载：(jb51.net).rar