取自ThinkPHP的文件缓存类代码，这里就不多废话了，小伙伴们自己看注释吧。

<?php

/**

* @desc 文件缓存

*/

class Cache{

const C_FILE = '/Runtime/';

private $dir = '';

const EXT = '.tpl';

private $filename = '';

public function __construct($dir = ''){

$this->dir = $dir;

}

/**

* @desc 设置文件缓存

* @param string $key 文件名

* @param unkonw $data 缓存数据

* @param int $expire 过期时间

*/

public function set($key,$data,$expire = 0){

$this->filename = dirname(__FILE__).self::C_FILE.$this->dir.$key.self::EXT;

if(file_exists($this->filename)){

$res = $this->get($key);

if(md5($res) == md5(json_encode($data) ) ){

return true;

}

}

if(!is_dir(dirname($this->filename))){

mkdir(dirname($this->filename),0777);

}

$source = fopen($this->filename,'w+');

fwrite($source,json_encode($data));

fclose($source);

}

/**

* @desc 获取文件

* @param string $key 文件名

*/

public function get($key){

//$filename = dirname(__FILE__).self::C_FILE.$this->dir.$key.self::EXT;

if(!file_exists($this->filename)){

return '缓存文件已经不存在';

}else{

$res = file_get_contents($this->filename);

}

return $res;

}

/**

* @desc 删除文件

* @param string $key 文件名

*/

public function del($key){

unlink($this->filename);

}

}

$data = array('name'=>'song','age'=>20,'sex'=>'man','favority'=>array('apple','banana'));

$cache = new Cache();

$cache->set('cache',$data);

//$cache->get('cache');

//$cache->del('cache');