我按照这个写法注入的dao，但是在执行的时候报空指针，是不是注入的方式不对？

@IocBean(args = {"refer:dao"})
public class UserTest extends TestBase {

    @Inject("refer:$ioc")
    protected Ioc ioc;
    @Test
    public void test4() {
        Dao dao = ioc.get(Dao.class);
        Sql sqlcount = Sqls.create("select t.area_id, count(t.area_id) as travel from t_visitor_locus t group by t.area_id order by travel desc ");
        sqlcount.setCallback(Sqls.callback.entity());
        sqlcount.setEntity(dao.getEntity(Record.class));
        dao.execute(sqlcount);
        Record countRecord=(Record) sqlcount.getResult();
        long count=(long) countRecord.get("area_id");
    }
}