//java代码
String url = url = "https://api.weixin.qq.com/sns/jscode2session?appid=" + appId +
"&secret=" + appSecret + "&js_code=" + code + "&grant_type=authorization_code";
//进行网络请求,访问url接口
ResponseEntity<String> responseEntity = restTemplate.exchange(url, HttpMethod.GET, null, String.class);
//结果
<200,{“errcode”:40029,“errmsg”:“invalid code, hints: [ req_id: ******* ]”},{Connection=[keep-alive], Content-Type=[text/plain], Date=[Mon, 23 Jul 2018 09:34:34 GMT], Content-Length=[76]}>