把java代码改成php代码，相当简单，只是根据简单的计数器返回一组信息！（摘自《ajax基础教程》）

你这个DynamicUpdateServlet类是继承HttpServlet的，怎么改啊？

解决方案 »

  1.   

    只要能接受数据的传入，然后再返回数据就可以了~~~我就是不清楚这个数据是怎么返回的~~~
    附客户端代码：
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>
      <head>
        <title>Ajax Dynamic Update</title>
        <script type="text/javascript">
            var xmlHttp;        function createXMLHttpRequest() {
                if (window.ActiveXObject) {
                    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
                } 
                else if (window.XMLHttpRequest) {
                    xmlHttp = new XMLHttpRequest();                
                }
            }
            
            function doStart() {
                createXMLHttpRequest();
                var url = "DynamicUpdateServlet?task=reset";
                xmlHttp.open("GET", url, true);
                xmlHttp.onreadystatechange = startCallback;
                xmlHttp.send(null);
            }        function startCallback() {
                if (xmlHttp.readyState == 4) {
                    if (xmlHttp.status == 200) {                    
                        setTimeout("pollServer()", 5000);
                        refreshTime();
                    }
                }
            }
            
            function pollServer() {
                createXMLHttpRequest();
                var url = "DynamicUpdateServlet?task=foo";
                xmlHttp.open("GET", url, true);
                xmlHttp.onreadystatechange = pollCallback;
                xmlHttp.send(null);
            }
            
            function refreshTime(){
                var time_span = document.getElementById("time");
                var time_val = time_span.innerHTML;            var int_val = parseInt(time_val);
                var new_int_val = int_val - 1;
                
                if (new_int_val > -1) {
                    setTimeout("refreshTime()", 1000);
                    time_span.innerHTML = new_int_val;                
                } else {
                    time_span.innerHTML = 5;
                }
            }
            
            function pollCallback() {
                if (xmlHttp.readyState == 4) {
                    if (xmlHttp.status == 200) {                
                        var message = xmlHttp.responseXML.getElementsByTagName("message")[0].firstChild.data;                    
                        
                        if (message != "done") {
                            var new_row = createRow(message);
                            var table = document.getElementById("dynamicUpdateArea");
                            var table_body = table.getElementsByTagName("tbody").item(0);
                            var first_row = table_body.getElementsByTagName("tr").item(1);
                            table_body.insertBefore(new_row, first_row);                        
                            setTimeout("pollServer()", 5000);
                            refreshTime();
                        }
                    }
                }
            }
            
            function createRow(message) {
                var row = document.createElement("tr");
                var cell = document.createElement("td");
                var cell_data = document.createTextNode(message);
                cell.appendChild(cell_data);
                row.appendChild(cell);
                return row;
            }
        </script>
      </head>
      <body>
        <h1>Ajax Dynamic Update Example</h1>
        This page will automatically update itself: 
            <input type="button" value="Launch" id="go" onclick="doStart();"/>
        <p>
        Page will refresh in <span id="time">5</span> seconds.
        <p>
        <table id="dynamicUpdateArea" align="left">
            <tbody>
                <tr id="row0"><td></td></tr>
            </tbody>
        </table>
      </body>
    </html>