微信入坑第二弹【自动回复消息上】

功能实现：

不管用户发送什么消息，都回复一条"谢谢您的关注"。

<span style="font-family:Courier New;font-size:14px;"><?php
define("TOKEN","weixin");
$weixinObj = new Wechat();
$weixinObj->valid();

class Wechat{
    public function valid(){
        $echoStr = $_GET['echostr'];
        //如果是第一次接入
        if($this->checkSignature() && $echoStr ){
            echo $echoStr;
            exit;
        }else{
        $this->responseMsg();
       }
    }
    //校验方法
    private function checkSignature(){
        $signature = $_GET['signature'];
        $timestamp = $_GET['timestamp'];
        $nonce = $_GET['nonce'];
        $token = TOKEN;

        $tmpArr = array($token, $timestamp, $nonce);
        sort($tmpArr);
        $tmpStr = implode($tmpArr);
        $tmpStr = sha1($tmpStr);
        if($tmpStr == $signature){
            return true;
        }else{
            return false;
        }
    }
/* 普通文本消息
<xml>
 <ToUserName><![CDATA[toUser]]></ToUserName>
 <FromUserName><![CDATA[fromUser]]></FromUserName>
 <CreateTime>1348831860</CreateTime>
 <MsgType><![CDATA[text]]></MsgType>
 <Content><![CDATA[this is a test]]></Content>
 <MsgId>1234567890123456</MsgId>
 </xml>
*/
    public function responseMsg(){
        //获取微信服务器POST请求中的数据
        
        $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
        if( !empty($postStr) ){
            $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA); 
            $fromUser = $postObj->FromUserName;
            $toUser = $postObj->ToUserName;
            $keyword = trim($postObj->Content);
            $time = time();
            
            $template = "<xml>
                         <ToUserName><![CDATA[%s]]></ToUserName>
                         <FromUserName><![CDATA[%s]]></FromUserName>
                         <CreateTime>%s</CreateTime>
                         <MsgType><![CDATA[%s]]></MsgType>
                         <Content><![CDATA[%s]]></Content>
                         </xml>";
            if( !empty($keyword) ){
                $msgType = 'text';
                $content = "谢谢您的关注";
                $info = sprintf($template, $fromUser, $toUser, $time, $msgType, $content);
                echo $info;
            }else{
                echo "请输入关键字";//消息为空
            }
        }else{
            echo "";
            exit;
        }
    }
}</span>