php微信开发(1)：缓存access_token的方法

语言：PHP

access_token一直要用，但每天取的数量有限制。反正2小时才过期。就想缓存一下。

File1: wx_access_token.php

File2: file_cache.php

---------------------------

File1: wx_access_token.php

<?php
/*
 * wx_access_token.php
 *
 * get the weixin access token
 * */
if (!defined("DOCUMENT_ROOT")) define("DOCUMENT_ROOT", $_SERVER['DOCUMENT_ROOT']);
if (!defined("__HOME__")) define("__HOME__", dirname(DOCUMENT_ROOT));

require_once("file_cache.php");

class WxAccessToken{
	public function getToken(){
		$wx_access_token_cache_key = 'wx_access_token';

		$cache = new FileCache(__HOME__ . '/myfolder/cache_file.txt');
		$token = $cache->get($wx_access_token_cache_key);

		if (!$token){
			$token = $this->getTokenFromWx();
			$cache->set($wx_access_token_cache_key, $token, time()+7000);
		}

		return $token;
	}

	private function getTokenFromWx(){
	        $appid = "your appid";
		$appsecret = "your app secret";
		$url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$appid&secret=$appsecret";
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, $url);
		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
		curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		$output = curl_exec($ch);
		curl_close($ch);

		$jsoninfo = json_decode($output, true);

		return $jsoninfo["access_token"];
	}
}
?>

File2: file_cache.php

<?php
/*
 * file_cache.php
 *
 * cache objects via json with filesystem
 * author: hydon lee
 * */

/*
class FileCache

examples:
	$cache = new FileCache('../myfolder/cache_file.txt');
	$cache->set('username', 'lihd', time()+3600);
	$username = $cache->get('username');
	echo $username;
*/
class FileCache{
	private $cache_file;

	private function load(){
		if(file_exists($this->cache_file)){
			$content = file_get_contents($this->cache_file);

			if (strlen($content) > 0){
				$data = json_decode($content);

				return $data;
			}
		}

		return array();
	}

	private function save($data){
		$content = json_encode($data);
		return file_put_contents($this->cache_file, $content);
	}

	public function __construct($filename) {
		$this->cache_file = $filename;
	}

	public function get($key){
		$data = $this->load();

		foreach($data as $item){
			if ($item->key == $key){
				if ($item->expire_time > time()){
					return $item->value;
				}

				break;
			}
		}

		return NULL;
	}

	public function set($key, $value, $expire_time=NULL){
		$data = $this->load();

		$obj = NULL;
		foreach($data as $item){
			if ($item->key == $key){
				$obj = $item;

				$obj->value = $value;
				if ($expire_time != NULL){
						$obj->expire_time = $expire_time;
				}

				break;
			}
		}

		if ($obj == NULL){
			$obj = new CacheItem($key, $value, $expire_time);
			array_push($data, $obj);
		}

		return $this->save($data);
	}
}

class CacheItem{
	public $key;
	public $value;
	public $expire_time;

	public function __construct($key, $value, $expire_time) {
		$this->key = $key;
		$this->value = $value;
		$this->expire_time = $expire_time;
	}
}
?>