H5页面获取openid，完成支付公众号(未关注公众号)支付

一、页面授权

　　

// 进入页面获取权限code
function initAuthorizeCode() {
	var appid = $("#appid").val();//公众号appid
	var openid = $("#openId").val();//openid
	var userId = $("#userId").val();
	var code = getUrlParam('code');
	var local = window.location.href;
	var hrefurl = "https://open.weixin.qq.com/connect/oauth2/authorize?appid="+appid+"&redirect_uri="+encodeURIComponent(local)+"&response_type=code&scope=snsapi_base&state=dcabe11a-751f-490f-9dcc-606881c6fcdb#wechat_redirect";
	var localopenid = localStorage.getItem("loginStorageKey"+userId);
	if((code==null || code == "")&&(openid==null||openid==""||openid=="null")){
		window.location.href = hrefurl;
//		window.location.replace(hrefurl);
	}else{
//		var localopenid = localStorage.getItem("loginStorageKey"+userId);
		if(openid==undefined || openid=="" || openid==null|| openid=="null"||openid=="undefined"){
			console.info(code);
			$.ajax({
				url: basePath+'loginController/getOpenId',
				type:'post',
				dataType:'json',
				data:{code:code},
				async:false,
				success:function(result){
					console.info(result);
					localStorage.setItem("loginStorageKey"+userId,result.openid);
					result = true;
				},
				error:function(msg){
					console.info(msg);
				},
			});
		}

	}
}

　　

二、通过code获取openid

	@RequestMapping(value = "/getOpenId")
	public @ResponseBody String getOpenId(HttpServletRequest request) {
		Map<String, Object> maps = new HashMap<String, Object>();
		maps.put("succ", true);
		maps.put("msg", "success");
		String code = request.getParameter("code");
		String openId = (String) request.getSession().getAttribute("wx_user_openid");
		try {
			// 调用查询接口 如果还是失败返回失败页面
			WxOauthLogin wxAuth = new WxOauthLogin();
			String url = wxAuth.getAccessTokenUrl(code);

			log.info("获取用户openid请求参数 result param:{}", url);

			URL urlObject = new URL(url);
			HttpURLConnection urlConnection = (HttpURLConnection) urlObject.openConnection();

			// 将返回的输入流转换成字符串
			InputStream inputStream = urlConnection.getInputStream();

			// 指定编码格式
			InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "UTF-8");
			BufferedReader in = new BufferedReader(inputStreamReader);
			String jsonUserStr = in.readLine().toString();

			// 释放资源
			inputStream.close();
			inputStream = null;
			urlConnection.disconnect();

			log.info("通过code换取网页授权access_token  result:{}", jsonUserStr);
			if (jsonUserStr != null) {
				Map<String, String> resultmap = Json.toObject(jsonUserStr, Map.class);
				if (StringUtil.empty(resultmap.get("openid"))) {
					log.error("获取openid失败");
					maps.put("succ", false);
					maps.put("msg", "获取openid失败");
				} else {
					maps.put("openid", resultmap.get("openid"));
					maps.put("unionid", resultmap.get("unionid"));
					// 将openId放到缓存
					 if(ObjectUtils.isEmpty(openId)){
						 openId = resultmap.get("openid");
						 request.getSession().setAttribute("wx_user_openid", openId);
						 maps.put("openid", openId);
					 }
				}
			}
		} catch (Exception e) {
			log.error("获取openid失败");
			maps.put("succ", false);
			maps.put("msg", "获取openid失败");
		}
		log.info("获取用户openid执行结果：{}",Json.toJson(maps));
		return Json.toJson(maps);
//		return openId;

	}

　　

三、根据code获取openid

 public String getAccessTokenUrl(String code) {
        // ?appid=APPID&secret=SECRET&code=CODE&grant_type=authorization_code
        StringBuffer url = new StringBuffer("https://api.weixin.qq.com/sns/oauth2/access_token");
        url.append("?appid=" + wxResourceProp.getAppid());
        url.append("&secret=" + wxResourceProp.getAppsecret());
        url.append("&code=" + code);
        url.append("&grant_type=authorization_code");
        return url.toString();
    }

　　

至此未关注公众号的微信用，可以用jsapi支付方式支付公众号里的订单。