獲取微信公眾號(hào)用戶的openid

發(fā)表時(shí)間：2020-11-6

發(fā)布人：葵宇科技

瀏覽次數(shù)：92

前言：

官方參考連接：https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/Wechat_webpage_authorization.html

1、用戶同意授權(quán)，獲取code

public void getCode(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//appid是公眾號(hào)的appid
		String redirect_uri=Param.local_url+"wx/openid";
		String url="https://open.weixin.qq.com/connect/oauth2/authorize?appid=" + appid + "&redirect_uri="
				+ URLEncoder.encode(redirect_uri, "GBK")
				+ "&response_type=code&scope=snsapi_base&state=STATE&connect_redirect=1#wechat_redirect";
		response.sendRedirect(url);
	}

需要注意的是鏈接需要用 URLEncoder.encode（url）進(jìn)行編碼，在連接中加入 connect_redirect=1 是防止網(wǎng)頁(yè)授權(quán)兩次或多次重定響應(yīng)問題，我這里的scope=snsapi_base不會(huì)彈出授權(quán)頁(yè)面，但只能拿到用戶的openid

2、在回調(diào)地址中通過code獲取用戶的openid

public void openid(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/xml; charset=UTF-8");
		String oauth2Url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=" + appid + "&secret=" + AppSecret
				+ "&code=" + request.getParameter("code") + "&grant_type=authorization_code";
		JSONObject jsonObject = JSONObject.fromObject(HttpRequestUtil.sendGet(oauth2Url));
		String pubopenid = jsonObject.getString("openid");
		System.out.println("獲取的openid"+pubopenid);
		
}

其中的sendGet()方法如下：

public static String sendGet(String url) {
        String result = "";
        BufferedReader in = null;
        try {
            URL realUrl = new URL(url);
            // 打開和URL之間的連接
            URLConnection connection = realUrl.openConnection();
            // 設(shè)置通用的請(qǐng)求屬性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立實(shí)際的連接
            connection.connect();
            // 獲取所有響應(yīng)頭字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍歷所有的響應(yīng)頭字段
            for (String key : map.keySet()) {
            }
            // 定義 BufferedReader輸入流來讀取URL的響應(yīng)
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
            	//System.out.println("jieguo--------幾萬(wàn)個(gè)"+result);
                result += line;
            }
        } catch (Exception e) {
            System.out.println("發(fā)送GET請(qǐng)求出現(xiàn)異常！" + e);
            e.printStackTrace();
        }
        // 使用finally塊來關(guān)閉輸入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }