微信公众号--进入菜单之前获取用户信息

1 String pinChe = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=MYAPPID&redirect_uri=http://ddiamondd.w3.luyouxia.net/WeChat/login&response_type=code&scope=snsapi_userinfo&state=STATE#wechat_redirect";
2 /*
3 很长的一个网址 其中appid和redirect_uri(授权后要跳转到的网页，可以是jsp或者servlet...)都要换成自己的，其他的不用变
4 */

/*
我上面的redirect_uri是跳转到一个servlet中
*/
@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String code = request.getParameter("code");
        AccessToken accessToken = WXService.getSpecialAccessToken(code); // 通过code换取网页授权access_token// 获取用户信息
        String url = "https://api.weixin.qq.com/sns/userinfo?access_token=ACCESS_TOKEN&openid=OPENID&lang=zh_CN";
        url2 = url.replace("ACCESS_TOKEN", accessToken.getAccessToken()).replace("OPENID", accessToken.getOpenId());
        String result = Util.get(url); // 获取到的用户信息
        JSONObject jsonObject = JSONObject.fromObject(result);
        String openid = jsonObject.getString("openid");
        request.getSession().setAttribute("openid", openid);
        request.getRequestDispatcher("/group/car.jsp").forward(request,response); // 跳转到对应页面上
}
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}