Java 微信小程序登录(openId方式)

1 需求
        在开发微信小程序项目时，登录采用的是openId方式，这是一种用户无感的登录方式，用户点开微信小程序时，去调用后端的登录接口。

核心代码

@Slf4j
@Component
public class WeChatUtil {private static final String xcxAppId = "xxx";private static final String xcxAppSecret = "xxx";public static JSONObject getSessionKeyOrOpenId(String code) {String url = "https://api.weixin.qq.com/sns/jscode2session";Map<String, String> params = new HashMap<>();params.put("appid", xcxAppId);params.put("secret", xcxAppSecret);params.put("js_code", code);params.put("grant_type", "authorization_code");return JSON.parseObject(HttpClientUtil.doPost(url, params));}
}

@Slf4j
@Service
public class UserService extends ServiceImpl<UserMapper, User> {public RequestResult login(Map<String, String> params) {String code = params.get("code");JSONObject weChatObject = WeChatUtil.getSessionKeyOrOpenId(code);String openId = weChatObject.getString("openid");if (StrUtil.isEmpty(openId)) {return RequestResult.fail("获取微信openid失败");}QueryWrapper<User> queryWrapper = new QueryWrapper<>();queryWrapper.eq("open_id", openId);User findUser = baseMapper.selectOne(queryWrapper);if (findUser != null) {findUser.setToken(JwtUtil.createTokenByUserIdOpenId(String.valueOf(findUser.getId()), openId));return RequestResult.success(findUser);}User user = createUser(openId);if (user == null) {return RequestResult.fail("用户信息初始化失败");}user.setToken(JwtUtil.createTokenByUserIdOpenId(String.valueOf(user.getId()), openId));return RequestResult.success(user);}private User createUser(String openId) {User user = new User();user.setOpenId(openId);user.setCreateTime(DateUtil.now());int result = baseMapper.insert(user);return result > 0 ? user : null;}
}