PHP用CURL发送Content-type为application/json的POST和GET请求方法

function json_post($url, $data = NULL)
    {

        $curl = curl_init();

        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        if(!$data){
            return 'data is null';
        }
        if(is_array($data))
        {
            $data = json_encode($data);
        }
        curl_setopt($curl, CURLOPT_POST, 1);
        curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        curl_setopt($curl, CURLOPT_HEADER, 0);
        curl_setopt($curl, CURLOPT_HTTPHEADER,array(
                'Content-Type: application/json; charset=utf-8',
                'Content-Length:' . strlen($data),
                'Cache-Control: no-cache',
                'Pragma: no-cache'
        ));
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        $res = curl_exec($curl);
        $errorno = curl_errno($curl);
        if ($errorno) {
            return $errorno;
        }
        curl_close($curl);
        return $res;

    }

 public function json_get($url){
        $header = array(
            'Accept: application/json',
        );
        $curl = curl_init();
        //设置抓取的url
        curl_setopt($curl, CURLOPT_URL, $url);
        //设置头文件的信息作为数据流输出
        curl_setopt($curl, CURLOPT_HEADER, 0);
        // 超时设置,以秒为单位
        curl_setopt($curl, CURLOPT_TIMEOUT, 1);

        // 超时设置，以毫秒为单位
        // curl_setopt($curl, CURLOPT_TIMEOUT_MS, 500);

        // 设置请求头
        curl_setopt($curl, CURLOPT_HTTPHEADER, $header);
        //设置获取的信息以文件流的形式返回，而不是直接输出。
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        //执行命令
        $data = curl_exec($curl);

        // 显示错误信息
        if (curl_error($curl)) {
            print "Error: " . curl_error($curl);
        } else {
            // 打印返回的内容
            curl_close($curl);
            return $data;
        }
    }