<?php ???$filename = "./jingtai.html";//定义一个变量来存放一个缓存文件的路径（相对于当前页面的路径） ???//定义缓存有效期 ???$cachetime = 10; ???//判断缓存文件是否存在 ??????????????????????????????????????var_dump(filemtime($filename)); ???????????????????????????????//filemtime($filename)不变,time()一直变，filemtime($filename)+10肯定会有小于time()的时候。 ???if(!file_exists($filename)||filemtime($filename)+$cachetime<time()){//filemtime($filename)获取文件修改时间，加上定义的缓存时间小于当前时间 ????????//开启内存缓存 ?????????????????????????????????//filemtime()该文件上次修改内容 ??????????????????????????????//filemtime($filename)第一次出现等于当前时间time();每过10秒走一次函数，filemtime($filename)的值就会改变 ???????var_dump(time()); ???????ob_start();?> ???<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ???<html xmlns="http://www.w3.org/1999/xhtml"> ???<head> ???<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> ???<title>无标题文档</title> ???</head> ???<body> ???????<table width="100%" border="1" cellpadding="0" cellspacing="0" > ???????????<tr> ???????????????<td>学号</td> ???????????????<td>姓名</td> ???????????????<td>性别</td> ???????????????<td>生日</td> ???????????????<td>班级</td> ???????????</tr> ????????<?php ???????????//造连接对象 ???????????$db = new MySQLi("localhost","root","","ceshi"); ???????????//写SQL语句 ???????????$sql = "select * from student"; ???????????//执行 ???????????$result = $db->query($sql); ???????????while($attr = $result->fetch_row()){ ???????????????echo "<tr> ???????????????????<td>{$attr[0]}</td> ???????????????????<td>{$attr[1]}</td> ???????????????????<td>{$attr[2]}</td> ???????????????????<td>{$attr[3]}</td> ???????????????????<td>{$attr[4]}</td> ???????????????????</tr>"; ???????????}?> ???????</table> ????</body> ???</html><?php ???????//从内存缓存中获取页面代码 ???????$content = ob_get_contents(); ???????//将获取到的内容存放到缓存文件 ???????file_put_contents($filename,$content); ???????//清掉内存缓存 ???????ob_flush(); ???????echo "#####"; ?//测试是否调用了缓存文件，缓存文件不输出这句话 ???} ???else{ ????????//var_dump(filemtime($filename)); var_dump(time()); ????????include($filename); ?//如果存在，调用缓存文件 ???} ?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> ???<html xmlns="http://www.w3.org/1999/xhtml"> ???<head> ???<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> ???<title>无标题文档</title> ???</head> ???<body> ???????<table width="100%" border="1" cellpadding="0" cellspacing="0" > ???????????<tr> ???????????????<td>学号</td> ???????????????<td>姓名</td> ???????????????<td>性别</td> ???????????????<td>生日</td> ???????????????<td>班级</td> ???????????</tr> ????????<tr> ???????????????????<td>1</td> ???????????????????<td>101</td> ???????????????????<td>王超</td> ???????????????????<td>男</td> ???????????????????<td>2000-02-12 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>2</td> ???????????????????<td>103</td> ???????????????????<td>陆君</td> ???????????????????<td>男</td> ???????????????????<td>1974-06-03 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>3</td> ???????????????????<td>105</td> ???????????????????<td>匡明</td> ???????????????????<td>男</td> ???????????????????<td>1975-10-02 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>4</td> ???????????????????<td>107</td> ???????????????????<td>王丽</td> ???????????????????<td>女</td> ???????????????????<td>1976-01-23 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>5</td> ???????????????????<td>108</td> ???????????????????<td>曾华</td> ???????????????????<td>男</td> ???????????????????<td>1977-09-01 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>6</td> ???????????????????<td>109</td> ???????????????????<td>王芳</td> ???????????????????<td>女</td> ???????????????????<td>1975-02-10 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>7</td> ???????????????????<td>110</td> ???????????????????<td>刘备</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>8</td> ???????????????????<td>111</td> ???????????????????<td>孙权1</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>9</td> ???????????????????<td>112</td> ???????????????????<td>曹操</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>10</td> ???????????????????<td>113</td> ???????????????????<td>刘邦</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>11</td> ???????????????????<td>114</td> ???????????????????<td>周瑜</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr><tr> ???????????????????<td>17</td> ???????????????????<td>098</td> ???????????????????<td>zhangsan32</td> ???????????????????<td>男</td> ???????????????????<td>0000-00-00 00:00:00</td> ???????????????????</tr> ???????</table> ????</body> ???</html>
7.20php文件缓存
原文地址：https://www.cnblogs.com/sunhao1987/p/9343725.html