thinkPHP3.2 method to implement WeChat access and query token value

<?php
/**
 * 微信父类控制器
 * @author Songle
 *
 */
namespace Weixin\Controller;
use Think\Controller;
class WeixinController extends Controller {
  private $last_time=null;
  private $appid=null;
  private $appsecret=null;
  function __construct(){
    parent::__construct();
    $token=C(&#39;TOKEN&#39;);
    $this->appid=C(&#39;APPID&#39;);
    $this->appsecret=C(&#39;APPSECRET&#39;);
    //获取微信服务器GET请求的4个参数
    $signature = I(&#39;signature&#39;);
    $timestamp = I(&#39;timestamp&#39;);
    $nonce = I(&#39;nonce&#39;);
    $echostr = I(&#39;echostr&#39;);
    if (! empty ( $echostr) && ! empty ( $signature ) && ! empty ($nonce )) {
      //定义一个数组，存储其中3个参数，分别是timestamp，nonce和token
      $tempArr = array($nonce,$timestamp,$token);
      //进行排序
      sort($tempArr,SORT_STRING);
      //将数组转换成字符串
      $tmpStr = implode($tempArr);
      //进行sha1加密算法
      $tmpStr = sha1($tmpStr);
      //判断请求是否来自微信服务器，对比$tmpStr和$signature
      if($tmpStr == $signature)
      {
        echo $echostr;
      }
      exit();
    }
  }
  /**
   * 获取tooken值
   */
  public function getTooken(){
    $this->last_time = 1448012924;
    $access_token = "填写上一次的token值"; //需要替换成自己的
    if(time() > ($this->last_time + 7200))
    {
      //GET请求的地址
      $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={$this->appid}&secret={$this->appsecret}";
      $access_token_Arr = $this->https_request($url);
      $this->last_time = time();
      return $access_token_Arr[&#39;access_token&#39;];
    }
    return $access_token;
  }
  //https请求（支持GET和POST）
  public function https_request($url,$data = null)
  {
    $ch = curl_init();
    curl_setopt($ch,CURLOPT_URL,$url);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
    if(!empty($data))
    {
      curl_setopt($ch,CURLOPT_POST,1); //模拟POST
      curl_setopt($ch,CURLOPT_POSTFIELDS,$data); //POST内容
    }
    $outopt = curl_exec($ch);
    curl_close($ch);
    $outopt = json_decode($outopt,true);
    return $outopt;
  }
}