主要用到了PHP中的 curl模块，分get和post两种方式。

<?php
/**
 * Created by PhpStorm.
 * User: dayue
 * Date: 2017/12/4
 * Time: 16:25
 */

namespace App\Services;


class ApiService
{
    static function reqUrl($url, $params = false, $ispost = 0)
    {
        $httpInfo = array();
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
        curl_setopt($ch, CURLOPT_USERAGENT, 'Data');
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 60);
        curl_setopt($ch, CURLOPT_TIMEOUT, 60);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
        if ($ispost) {
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $params);
            curl_setopt($ch, CURLOPT_URL, $url);
        } else {
            if ($params) {
                curl_setopt($ch, CURLOPT_URL, $url . '?' . $params);
            } else {
                curl_setopt($ch, CURLOPT_URL, $url);
            }
        }
        $response = curl_exec($ch);
        if ($response === FALSE) {
            //echo "cURL Error: " . curl_error($ch);
            return false;
        }
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        // dd($httpCode);
        $httpInfo = array_merge($httpInfo, curl_getinfo($ch));
        // dd($httpInfo);
        curl_close($ch);
        $response = json_decode($response,true);
        $result = [];
        $result['httpCode'] = $httpCode;
        $result['info'] = $response;
        return $result;

        // $data_string = json_encode($params);
        //
        // $ch = curl_init($url);
        // curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
        // curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
        // curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        // curl_setopt($ch, CURLOPT_HTTPHEADER, array(
        //         'Content-Type: application/json',
        //         'Content-Length: ' . strlen($data_string))
        // );
        //
        // $result = json_decode(curl_exec($ch), true);
        //
        // curl_close($ch);
        // return $result;
    }
}

//json接口测试用例
public function ApiTest()
{
    $url = 'http://ip.taobao.com/service/getIpInfo.php';
    $params = 'ip=101.81.71.12';
    $res = ApiService::reqUrl($url, $params);
    return $res['info']['data'];
}

JSON API免费接口