我在使用的时候，调用的WxApi2 getWxApi2没有拿到access_token，
然后我里看到有人用这个@SetupBy，我就放到了前面就能正常获取到了，但是我怕access_token过期，和重复掉去交换access_token，

有时候，不知道怎么的一段时间access_token就是拿到了，这个是为什么？

@IocBean(args = {"refer:dao"})
@SetupBy
public class WxConfigService extends Service<Wx_config> {
    public WxConfigService(Dao dao) {
        super(dao);
    }

    public WxApi2 getWxApi2(String wxid) {
        Wx_config appInfo = this.fetch(Cnd.where("id", "=", wxid));
        DaoAccessTokenStore myDaoAccessTokenStore = new DaoAccessTokenStore(dao());
        Map<String, Object> params = new HashMap<>();
        params.put("id", appInfo.getId());
        myDaoAccessTokenStore.setTableAccessToken("access_token");
        myDaoAccessTokenStore.setTableAccessTokenExpires("access_token_expires");
        myDaoAccessTokenStore.setTableAccessTokenLastat("access_token_lastat");
        myDaoAccessTokenStore.setFetch("select access_token,access_token_expires,access_token_lastat from wx_config where id=@id");
        myDaoAccessTokenStore.setUpdate("update wx_config set access_token=@access_token, access_token_expires=@access_token_expires, access_token_lastat=@access_token_lastat where id=@id");
        myDaoAccessTokenStore.setParams(params);
        WxApi2Impl wxApi2 = new WxApi2Impl();
        wxApi2.setAppid(appInfo.getAppid());
        wxApi2.setAppsecret(appInfo.getAppsecret());
        wxApi2.setEncodingAesKey(appInfo.getEncodingAESKey());
        wxApi2.setToken(appInfo.getToken());
        wxApi2.setAccessTokenStore(myDaoAccessTokenStore);
        return wxApi2;
    }
}