<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script src="http://code.jquery.com/jquery-2.1.4.min.js"></script>
</head>
<body>
<div id="msg"></div>
</body>
</html>
<script>
setInterval('getdata()',5000);//轮询执行，500ms一次
// getdata();
function getdata(){
$.ajax({
type: "POST",
dataType: "json",
url: "t.php",
timeout: 80000, //ajax请求超时时间80秒
// data: {time: "40"}, //40秒后无论结果服务器都返回数据
success: function (data, textStatus) {
//从服务器得到数据，显示数据并继续查询
if (data.success == "1") {
$("#msg").append("<br>[有数据]" + data.text);
evdata.data.btn.click();
}
//未从服务器得到数据，继续查询
if (data.success == "0") {
$("#msg").append("<br>[无数据]");
getdata();
}
},
//Ajax请求超时，继续查询
error: function (XMLHttpRequest, textStatus, errorThrown) {
if (textStatus == "timeout") {
$("#msg").append("<br>[超时]");
evdata.data.btn.click();
}
}
});
}
</script>
<?php
echo json_encode(['success'=>1,'text'=>'datadatadatadatadatadatadatadatadatadatadatadatadata']);die;
?>