微信开发之获取JSAPI TICKET

一、获取流程

1、获取 access_token

2、通过access_token换取 jsapi_ticket

3、签名算法

签名生成规则如下：参与签名的字段包括noncestr（随机字符串）, 有效的jsapi_ticket, timestamp（时间戳）, url（当前网页的URL，不包含#及其后面部分）。对所有待签名参数按照字段名的ASCII 码从小到大排序（字典序）后，使用URL键值对的格式（即key1=value1&key2=value2…）拼接成字符串string1。这里需要注意的是所有参数名均为小写字符。对string1作sha1加密，字段名和字段值都采用原始值，不进行URL 转义。

二、具体实现方式

1、获取access_token

				?

									/**

									 * [getAccessToken description] 获取access_token

									 * @return [type] [description] */private function getAccessToken() {

									  $data = $this->getFile($this->accessTokenFile);  if(time() - $data['time'] > 0){

									    $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={$this->appID}&secret={$this->appsecret}";

									    $re = $this->httpGet($url);

									    $access_token = $re['access_token'];    

									    if(isset($access_token)){

									      $data['access_token'] = $access_token;

									      $data['time'] = time() + 7200;

									      $this->setFile($this->accessTokenFile,json_encode($data));

									    }

									  }else{

									    $access_token = $data['access_token'];

									  }  return $access_token;

									}

access_token 的有效时间是7200s，故可以采用文件存储的方法进行保存，避免多次请求；

2、获取jsapi_ticket

				?

									/**

									 * [getJsapiTicket description] 获取jsapi_ticket

									 * @return [type] [description] */private function getJsapiTicket() {

									  $access_token = $this->getAccessToken();

									  $jsapi_ticket = $this->getFile($this->jsapiTicketFile);  if(time() - $jsapi_ticket['time'] > 0) {

									    $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token={$access_token}&type=jsapi";

									    $re = $this->httpGet($url);

									    $this->preArr($re);

									    $jsapi_ticket = $re['ticket'];    

									    if(isset($jsapi_ticket)){

									      $data['jsapi_ticket'] = $jsapi_ticket;

									      $data['time'] = time() + 7200;

									      $this->setFile($this->jsapiTicketFile, json_encode($data));

									    }

									  }else{

									    $jsapi_ticket = $jsapi_ticket['jsapi_ticket'];

									  }  return $jsapi_ticket;

									}

通过access_token进行交换，得到jsapi_ticket，有效期也是7200s；

3、生成签名

				?

									/**

									 * [getSignpackage description] 获取签名

									 * @return [type] [description] */public function getSignpackage(){

									  $jsapi_ticket = $this->getJsapiTicket();  // 注意 URL 一定要动态获取，不能 hardcode.

									  $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";

									  $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

									  $noncestr = $this->createNonceStr();

									  $timestamp = time();

									  $string1 = "jsapi_ticket={$jsapi_ticket}&noncestr={$noncestr}&timestamp={$timestamp}&url={$url}";

									  $signature = sha1($string1);  

									  $signPackage = array(    

									    'appId'   => $this->appID,    

									    'nonceStr' => $noncestr,    

									    'timestamp' => $timestamp,    

									    'signature' => $signature,

									  );  

									  return $signPackage;

									}