流程：
使用者點選選單按鈕
—–> 傳送頁面授權請求到微信後臺
—–>得到code傳送到 我們伺服器後臺的url
—–> 將code引數傳送到微信後臺獲取使用者的openid返回伺服器上的頁面(也可以直接獲取使用者頭像等基本資訊。。需使用者點選同意授權)

選單view按鈕的url：

“https://open.weixin.qq.com/connect/oauth2/authorize?appid=“+yourAppid+”&redirect_uri=”+你要跳轉的url+”&response_type=code&scope=snsapi_base&state=1#wechat_redirect”

你要跳轉的url 請求到後臺 獲取頁面授權的code

    String code = request.getParameter("code");// 頁面授權獲取的code用以交換openid額access_token
    openid = OAuthGetOpenid(code);// OAuth獲取使用者openid區分是哪個使用者請求登入W3

/**
 * 通過頁面OAuth授權,用code獲取openid
 * 
 * @param code
 * @return
 */
public String OAuthGetOpenid(String code) {
    JSONObject json = new JSONObject();
    String requestUrl = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=你的公眾號id&secret=你的公眾號密碼&code=" + code + "&grant_type=authorization_code";
    String outputStr = "";
    new HttpRequestPost();
    json = HttpRequestPost.httpRequest(requestUrl, outputStr, "POST");
    String openid = json.getString("openid");
    return openid;
}
 

傳送http請求的方法程式碼

/***
 * 向微信端傳送post請求
 *
 */
public class HttpRequestPost {

    public static JSONObject httpRequest(String requestUrl, String outputStr, String method) {
        JSONObject jsonObject = null;
        StringBuffer buffer = new StringBuffer();
        try {
            // // 建立SSLContext物件，並使用我們指定的信任管理器初始化
 

            // TrustManager[] tm = { new MyX509TrustManager() };
            // SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
            // sslContext.init(null, tm, new java.security.SecureRandom());
            // 從上述SSLContext物件中得到SSLSocketFactory物件
            // SSLSocketFactory ssf = sslContext.getSocketFactory();

            URL url = new URL(requestUrl);
            HttpsURLConnection httpUrlConn = (HttpsURLConnection) url.openConnection();
            // httpUrlConn.setSSLSocketFactory(ssf);

            httpUrlConn.setDoOutput(true);
            httpUrlConn.setDoInput(true);
            httpUrlConn.setUseCaches(false);
            // 設定請求方式（GET/POST）
            httpUrlConn.setRequestMethod(method);
            httpUrlConn.connect();

            // 當有資料需要提交時
            if (null != outputStr) {
                OutputStream outputStream = httpUrlConn.getOutputStream();
                // 注意編碼格式，防止中文亂碼
                outputStream.write(outputStr.getBytes("UTF-8"));
                outputStream.close();
            }
            // 將返回的輸入流轉換成字串
            InputStream inputStream = httpUrlConn.getInputStream();
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

            String str = null;
            while ((str = bufferedReader.readLine()) != null) {
                buffer.append(str);
            }
            bufferedReader.close();
            inputStreamReader.close();
            // 釋放資源
            inputStream.close();
            inputStream = null;
            httpUrlConn.disconnect();
            jsonObject = JSONObject.fromObject(buffer.toString());
            System.out.println("http-back:" + jsonObject);
        } catch (ConnectException ce) {
            System.err.println("Weixin server connection timed out.");
        } catch (Exception e) {
            System.err.println("https request error:{}" + e);
        }
        return jsonObject;
    }
}