Ajax制作Web进度条

Ajax制作Web进度条

1.index.jsp

Ajax制作Web进度条
1 <%@ page language="java" pageEncoding="UTF-8"%>
  2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
  3 <html>
  4   <head>
  5     <script type="text/javascript" language="javaScript">
  6       var bgcolor = '#7FFF00'; //全局变量,用于设置进度条的背景色
  7       var number; //全局变量,用于记录当前span序号
  8       var clear = "&nbsp;&nbsp;&nbsp;"; //全局变量,记录清空时的内容
  9       var xmlHttp = false; //全局变量,用于记录XMLHttpRequest对象
 10       function createXMLHttpRequest() { //创建XMLHttpRequest对象的方法
 11         if(window.ActiveXObject) { //Inetrnet Explorer时,创建XMLHttpRequest对象的方法
 12           try {
 13             xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
 14           } catch(e) {
 15             try {
 16               xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
 17                //旧版本的Inetrnet Explorer,创建XMLHttpRequest对象
 18             } catch(e) {
 19               window.alert("创建XMLHttpRequest对象错误"+e);
 20             } 
 21           }
 22         } else if(window.XMLHttpRequest) { //mozilla时,创建XMLHttpRequest对象的方法
 23           xmlHttp = new XMLHttpRequest();
 24         } 
 25         if(!(xmlHttp)) { //未成功创建XMLHttpRequest对象
 26             window.alert("创建XMLHttpRequest对象异常!");
 27         }  
 28       }
 29 
 30       //启动进度条的方法
 31       function startRun() {
 32         createXMLHttpRequest(); //创建XMLHttpRequest对象
 33         clearBar(); //执行请求前先清除进度条
 34         xmlHttp.onreadystatechange = callBack;
 35         //指定onreadystatechange属性值,用于指定状态正常时的处理函数
 36         xmlHttp.open("GET", "/ProgressTest/servlet/ProcessServlet?flag=start", true);
 37         xmlHttp.send(null);
 38       }
 39       
 40       //开始进行进度条显示的处理函数
 41       function callBack() {
 42           //window.alert("callBack()");
 43         if(xmlHttp.readyState == 4) {
 44            if(xmlHttp.status == 200) { //status状态正常时
 45              setTimeout("aginRun()",1000);
 46             //每隔1000毫秒(1秒)执行一次“aginRun()”函数
 47            }
 48         }
 49       }
 50 
 51       //清除用于显示进度条的span的内容
 52       function clearBar() {
 53         for (var i=0;i<10;i++) { //根据span元素的id,分别清楚其显示内容
 54           var sp = document.getElementById("sp" + i);
 55           sp.innerHTML = clear; //首先清空span元素的内容
 56           sp.style.backgroundColor = "white"; //设置span元素的背景色
 57         }
 58       }
 59       //设置用于显示进度条的span元素的显示内容
 60       function aginRun() {
 61         createXMLHttpRequest(); //创建XMLHttpRequest对象
 62         xmlHttp.onreadystatechange = aginCallBack;
 63         //指定状态正常时的处理函数为“aginCallBack”
 64         document.getElementById("run").disabled=true; //设置按钮不可用
 65         xmlHttp.open("GET", "/ProgressTest/servlet/ProcessServlet?flag=run", true);
 66         //window.alert(" " + number);
 67         xmlHttp.send(null);
 68       }
 69 
 70       //进度条执行时的函数
 71       function aginCallBack() {
 72         if(xmlHttp.readyState==4) {
 73           if(xmlHttp.status==200) {
 74             var percent = 
 75             xmlHttp.responseXML.getElementsByTagName("percent")[0].firstChild.data;
 76            //记录当前完成比例
 77             var index = parseResult(percent); //解析结果集
 78             var nextCell = 1;
 79             for (var i=0; i<index; i++) { //遍历span元素集合,设置其内容(颜色与文字)
 80               var sp = document.getElementById("sp"+i);
 81             //根据每个span元素的id获取span对象
 82               sp.innerHTML= clear; //清空span元素内容
 83               sp.style.backgroundColor = bgcolor; //设置span元素的内容
 84               nextCell = i+1;
 85               if(nextCell>=index && nextCell<10) { //显示当前处理进度的百分比
 86                 document.getElementById("sp"+nextCell).innerHTML=percent+"%";
 87               }
 88             }
 89             if(index<10) { //索引小于10,设置setTimeout方法
 90                setTimeout("aginRun()",1000);
 91             } else { //索引大于10,设置进度条成功完成的页面效果
 92                document.getElementById("result").innerHTML = "OK!";
 93                document.getElementById("run").disabled = false;
 94             }
 95           }
 96         }
 97       }
 98 
 99       //解析结果集
100       function parseResult(result) {
101         if(result.length<1) {
102           return 1;
103         } else if(result.length==2) {
104           return result.substring(0,1);
105         } else {
106           return 10;
107         }
108       }
109     </script>
110     <title>Ajax进度条</title>
111   </head>
112   <body>
113    <table align="center">
114             <tr>
115               <td>Ajax进度条示例&nbsp;&nbsp;&nbsp;<input type="button" value="开始" id="run" onclick="startRun();"/></td>
116             </tr>
117             <tr>
118               <td>
119               <div id="processBar" style="padding:1px;border:solid black 1px;">
120                <span id="sp0">&nbsp;&nbsp;&nbsp;</span>
121                <span id="sp1">&nbsp;&nbsp;&nbsp;</span>
122                <span id="sp2">&nbsp;&nbsp;&nbsp;</span>
123                <span id="sp3">&nbsp;&nbsp;&nbsp;</span>
124                <span id="sp4">&nbsp;&nbsp;&nbsp;</span>
125                <span id="sp5">&nbsp;&nbsp;&nbsp;</span>
126                <span id="sp6">&nbsp;&nbsp;&nbsp;</span>
127                <span id="sp7">&nbsp;&nbsp;&nbsp;</span>
128                <span id="sp8">&nbsp;&nbsp;&nbsp;</span>
129                <span id="sp9">&nbsp;&nbsp;&nbsp;</span>
130               </div>
131               </td>
132             </tr>
133             <tr><td align="center" id="result"></td> </tr>
134     </table>
135   </body>
136 </html>
Ajax制作Web进度条

2.ProcessServlet.java

Ajax制作Web进度条
1 public class ProcessServlet extends HttpServlet {
 2     
 3     private static final String CONTENT_TYPE = "text/xml; charset=UTF-8";
 4 //设置返回响应的ContentType
 5     private int count = 1;// 全局变量计数器
 6     /**
 7      *当前Servlet对象构造方法
 8      */
 9     public ProcessServlet() {
10         super();
11     }
12     /**
13      *当前Servlet销毁时的操作。<br>
14      */
15     public void destroy() {
16         super.destroy();
17     }
18     /**
19      *当前Servlet的doGet方法。<br>
20      *
21      *当客户端表单的“method”类型为“get”时,调用此方法
22      * 
23      * @param request客户端请求对象
24      * @param response 服务器响应对象
25      * @throws ServletException 发生ServeltException时抛出
26      * @throws IOException发生IOException时抛出
27      */
28     public void doGet(HttpServletRequest request, HttpServletResponse response)
29             throws ServletException, IOException {
30         System.out.println("*********************doGet()**********");
31         response.setContentType(CONTENT_TYPE); //设置服务器响应类型
32         response.setHeader("Cache-Control","no-cache"); //页面不记录缓存
33         String flag = request.getParameter("flag"); //操作类型
34         StringBuffer xml= 
35 //            new StringBuffer("<?xml version=\"1.0\" encoding=\"UTF-8\"?><items>");
36             new StringBuffer("<items>");
37         //记录返回的xml串
38         if("start".equals(flag)) { //第一次创建
39 //            xml.append("<count>1</count>");
40             count = 1;
41         } else {
42             String proportion = "";
43             switch(count) { //根据计数器的值,设置显示当前进度的百分比
44               case 1:proportion="10"; break;
45               case 2:proportion="20"; break;
46               case 3:proportion="30"; break;
47               case 4:proportion="40"; break;
48               case 5:proportion="50"; break;
49               case 6:proportion="60"; break;
50               case 7:proportion="70"; break;
51               case 8:proportion="80"; break;
52               case 9:proportion="90"; break;
53               case 10:proportion="100"; break;
54             }
55             count++;
56             xml.append("<percent>").append(proportion).append("</percent>");
57         }
58         xml.append("</items>");
59         PrintWriter out = response.getWriter();
60         out.println(xml.toString()); //返回生成的XML串
61         out.flush(); //输出流刷新
62         out.close(); //关闭输出流
63         System.out.println("*********** " + xml.toString());
64     }
65 
66     /**
67      * 初始化servlet. <br>
68      * @throws ServletException 发生ServletExcpetio异常时抛出
69      */
70     public void init() throws ServletException {
71     }
72 }
Ajax制作Web进度条

3.web.xml

Ajax制作Web进度条
1 <?xml version="1.0" encoding="UTF-8"?>
 2 <web-app version="2.5" 
 3     xmlns="http://java.sun.com/xml/ns/javaee" 
 4     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 5     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 6     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 7     <servlet>
 8     <servlet-name>ProcessServlet</servlet-name>
 9     <servlet-class>wen.ProcessServlet</servlet-class>
10   </servlet>
11   <servlet-mapping>
12     <servlet-name>ProcessServlet</servlet-name>
13     <url-pattern>/servlet/ProcessServlet</url-pattern>
14   </servlet-mapping>
15     
16   <welcome-file-list>
17     <welcome-file>index.jsp</welcome-file>
18   </welcome-file-list>
19 </web-app>
Ajax制作Web进度条

相关推荐