本文主要示範Jquery progressbar的進度條功能。js通過ajax請求向後台即時擷取當前的進度值。後台將進度值儲存在cookie中，每次請求後，將進度條的值增2個。以此示範進度條的即時顯示功能。
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，實現進度條的即時更新 timerId=window.setInterval(getForm,500); }); function getForm(){ //使用JQuery從後台擷取JSON格式的資料 $.ajax({ type:"post",//請求方式 url:"getProgressValueByJson",//發送請求地址 timeout:30000,//逾時時間：30秒 dataType:"json",//設定返回資料的格式 //請求成功後的回呼函數 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>
struts.xml檔案的配置
<?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>
背景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擷取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(); } } /** * 擷取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; } /** * 設定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(); } }}
運行
將項目部署到Tomcat上之後，在瀏覽器中輸入URL，則可以看到進度條逐漸更新
源碼下載：http://xiazai.jb51.net/201610/yuanma/jqueryProgressbar(jb51.net).rar
以上就是本文的全部內容，希望對大家的學習有所協助，也希望大家多多支援雲棲社區。
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