微信用户公众授权登录获取openid（微信公众号开发获取openid）

package com.yzy.sell.Controller;

import com.yzy.sell.Enums.ResultEnum;
import com.yzy.sell.exception.SellException;
import lombok.extern.slf4j.Slf4j;
import me.chanjar.weixin.common.api.WxConsts;
import me.chanjar.weixin.common.error.WxErrorException;
import me.chanjar.weixin.mp.api.WxMpService;
import me.chanjar.weixin.mp.bean.result.WxMpOAuth2AccessToken;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import java.net.URLEncoder;

@Controller
@Slf4j
@RequestMapping("/wechat")
public class WecharController {

    @Autowired
    private  WxMpService wxMpService;
    @GetMapping("/authorize")    //获取code
    public String authorize(@RequestParam("returnUrl") String returnUrl){
        String redirectUrl="http://shouyaya.natapp1.cc/sell/wechat/userInfo";
        String resultRedirectUrl = wxMpService.oauth2buildAuthorizationUrl(redirectUrl,
                WxConsts.OAuth2Scope.SNSAPI_BASE,
                URLEncoder.encode(returnUrl));//该属性对应微信接口里的state属性，
        // 通过此属性可以传递自定义参数，这里定义了从前端获取ip地址
        log.info("[回调的地址为：{}]",resultRedirectUrl);
        return "redirect:"+resultRedirectUrl;

    }
    @GetMapping("/userInfo")   //通过前面获取的code，以oauth2getAccessToken获取wxMpOAuth2AccessToken
                                //openid即可通过wxMpOAuth2AccessToken获取
    public String userInfo(@RequestParam("code") String code,@RequestParam("state") String returnUrl){
        WxMpOAuth2AccessToken wxMpOAuth2AccessToken= new WxMpOAuth2AccessToken();
        try {
             wxMpOAuth2AccessToken = wxMpService.oauth2getAccessToken(code);

        } catch (WxErrorException e) {
            log.error("【微信网页授权】,{}", e);
            throw new SellException(ResultEnum.WECHAT_MP_ERROR.getCode(),e.getError().getErrorMsg());
        }
        String openId = wxMpOAuth2AccessToken.getOpenId();
        log.info("openId={}",openId);
        return "redirect:"+returnUrl+"?openid="+openId;
    }
}