html代码
<!DOCTYPE html>
<html>
<head>
<title>Ajax Thread</title>
<meta charset="utf-8"/>
</head>
<body>
<div>Comet return:</div>
start:<div id="start"> </div>
get:<div id="get"> </div>
sended:<div id="sended"> </div>
pause:<div id="pause"> </div>
callback:<div id="callback"> </div>
pause2:<div id="pause2"> </div>
<script type="text/javascript">
if (!window.console) {
var console = {
log: function() {}
};
}
var xmlhttp;
function loadXMLDoc(url, callback) {
xmlhttp = null;
if (window.XMLHttpRequest) { // code for IE7, Firefox, Opera, etc.
xmlhttp = new XMLHttpRequest();
} else if (window.ActiveXObject) { // code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlhttp != null) {
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4) { // 4 = "loaded"
if (xmlhttp.status == 200) { // 200 = "OK"
//dom(‘A1‘).innerHTML = xmlhttp.status;
//dom(‘A2‘).innerHTML = xmlhttp.statusText;
//dom(‘A3‘).innerHTML = xmlhttp.responseText;
callback(xmlhttp.responseText);
} else {
//alert("Problem retrieving XML data:" + xmlhttp.statusText);
}
}
}
xmlhttp.open("GET", url, true);
xmlhttp.send(null);
} else {
//alert("Your browser does not support XMLHTTP.");
}
}
function pause(numberMillis, id) {
var now = new Date();
var exitTime = now.getTime() + numberMillis;
var count = 0;
var lastTime = parseInt(now.getTime() / 1000);
while (true) {
now = new Date();
if (lastTime == parseInt(now.getTime() / 1000)) {
count++;
} else {
dom(id).innerHTML = dom(id).innerHTML + lastTime + ‘ ‘ + count + ‘<br>‘;
console.log(id, lastTime, count);
lastTime = parseInt(now.getTime() / 1000);
count = 0;
}
if (now.getTime() > exitTime) {
return;
}
}
}
function dom(id) {
return document.getElementById(id);
}
(function() {
dom("start").innerHTML = parseInt(new Date().getTime() / 1000);
console.log(‘start‘, parseInt(new Date().getTime() / 1000));
loadXMLDoc("/get.php?" + Math.random(), function(data) {
console.log(‘callback‘, parseInt(new Date().getTime() / 1000));
dom("callback").innerHTML = dom("callback").innerHTML + ‘--我在前面是ajax是同步执行--‘;
dom("callback").innerHTML = dom("callback").innerHTML + parseInt(new Date().getTime() / 1000);
dom("get").innerHTML = data + ‘<br>‘;
pause(2000, ‘pause2‘);
});
dom("sended").innerHTML = parseInt(new Date().getTime() / 1000);
dom("callback").innerHTML = dom("callback").innerHTML + ‘--我在前面是ajax是异步执行--‘;
console.log(‘sended‘, parseInt(new Date().getTime() / 1000));
pause(6000, ‘pause‘);
})();
</script>
</body>
</html>
php代码
<?php $s = time(); sleep(4); echo "i am coming! "; echo "get:".$s." send:".time(); ?>
输出结果
时间： 2024-10-25 05:36:02